Patentability

2105	Patentable Subject Matter - Living Subject 
Matter 

2106	Patentable Subject Matter - Computer-Related 
Inventions 

2106.01	Computer Programming and 35 U.S.C. 112, 
First Paragraph 

2106.02	Disclosure in Computer  Programming Cases 

2107	General Principles Governing Utility 
Rejections 

2107.01	Procedural Considerations Related to 
Rejections for Lack of Utility 

2107.02	Special Considerations for Asserted 
Therapeutic or Pharmacological Utilities 

2111	Claim Interpretation; Broadest  Reasonable 
Interpretation  

2111.01	Plain Meaning 

2111.02	Weight of Preamble 

2111.03	Transitional Phrases 

2112	Requirements of Rejection Based on Inherency; 
Burden of Proof 

2112.01	Composition, Product, and  Apparatus Claims 

2112.02	Process Claims

2113	Product-by-Process Claims 

2114	Apparatus and Article Claims - Functional 
Language 

2115	Material or Article Worked Upon by 
Apparatus 

2116	Material Manipulated in Process 

2116.01	Novel, Unobvious Starting Material or End 
Product 

2121	Prior Art; General Level of Operability 
Required to Make a Prima Facie Case 

2121.01	Use of Prior Art in Rejections Where 
Operability Is in Question 

2121.02	Compounds and Compositions - What 
Constitutes Enabling Prior  Art 

2121.03	Plant Genetics - What Constitutes Enabling 
Prior Art 

2121.04	Apparatus and Articles - What Constitutes 
Enabling Prior Art 

2122	Discussion of Utility in the Prior Art  

2123	Rejection Over Prior Art's Broad Disclosure 
Instead of Preferred Embodiments 

2124	Exception to the Rule That the Critical 
Reference Date Must Precede the Filing Date 

2125	Drawings as Prior Art 

2126	Availability of a Document as a "Patent" for 
Purposes of Rejection Under 35 U.S.C. 102(a), 
(b), and (d)  

2126.01	Date of Availability of a Patent As a  Reference 

2126.02	Scope of Reference's Disclosure  Which Can 
Be Used to Reject  Claims When the Reference 
Is a  "Patent" but Not a "Publication"  

2127	Domestic and Foreign Patent  Applications as 
Prior Art   

2128	"Printed Publications" as Prior Art 

2128.01	Level of Public Accessibility  Required 

2128.02	Date Publication Is Available as a Reference  

2129	Admissions as Prior Art  

2131	Anticipation - Application of 35 U.S.C.  102(a), 
(b), and (e)  

2131.01	Multiple Reference 35 U.S.C. 102 Rejections  

2131.02	Genus-Species Situations  

2131.03	Anticipation of Ranges 

2131.04	Secondary Considerations 

2131.05	Nonanalogous Art  

2132	35 U.S.C. 102(a)  

2132.01	Publications as 35 U.S.C. 102(a) Prior Art  

2133	35 U.S.C. 102(b) 

2133.01	Rejections of Continuation-In-Part (CIP) 
Applications 

2133.02	Rejections Based on Publications and Patents  

2133.03	Rejections Based on "Public Use" or "On Sale"

2133.03(a)	"Public Use"  

2133.03(b)	"On Sale"  

2133.03(c)	The "Invention" 

2133.03(d)	"In This Country"  

2133.03(e)	Permitted Activity; Experimental Use 

2133.03(e)(1)	Commercial Exploitation 

2133.03(e)(2)	Intent 

2133.03(e)(3)	"Completeness" of the Invention  

2133.03(e)(4)	Factors Indicative of an  Experimental 
Purpose 

2133.03(e)(5)	Experimentation and Degree of Supervision 
and Control  

2133.03(e)(6)	Permitted Experimental  Activity and 
Testing  

2133.03(e)(7)	Activity of an Independent Third Party 
Inventor 

2134	35 U.S.C. 102(c) 

2135	35 U.S.C. 102(d)  

2135.01	The Four Requirements of  35 U.S.C. 102(d)  

2136	35 U.S.C. 102(e)  

2136.01	Status of U.S. Patent as a Reference Before and 
After  Issuance 

2136.02	Content of the Prior Art Available Against the 
Claims  

2136.03	Critical Reference Date  

2136.04	Different Inventive Entity; Meaning of "By 
Another"  

2136.05	Overcoming a Rejection Under  35 U.S.C. 
102(e)  

2137	35 U.S.C. 102(f)  

2137.01	Inventorship   

2137.02	Applicability of 35 U.S.C. 103(c)  

2138	35 U.S.C. 102(g)  

2138.01	Interference Practice  

2138.02	"The Invention Was Made in This Country"  

2138.03	"By Another Who Has Not Abandoned, 
Suppressed, or  Concealed It"  

2138.04	"Conception"  

2138.05	"Reduction to Practice"  

2138.06	"Reasonable Diligence"  

2141	35 U.S.C. 103; The Graham Factual Inquiries  

2141.01	Scope and Content of the Prior Art  

2141.01(a)	Analogous and Nonanalogous Art  

2141.02	Differences Between Prior Art and Claimed 
Invention  

2141.03	Level of Ordinary Skill in the Art 

2142	Legal Concept of Prima Facie  Obviousness  

2143	Basic Requirements of a Prima Facie Case of 
Obviousness  

2143.01	Suggestion or Motivation to Modify the 
References  

2143.02	Reasonable Expectation of Success Is Required  

2143.03	All Claim Limitations Must Be Taught or 
Suggested  

2144	Sources of Rationale Supporting a Rejection 
Under 35 U.S.C. 103  

2144.01	Implicit Disclosure  

2144.02	Reliance on Scientific Theory  

2144.03	Reliance on Common Knowledge in the Art or 
"Well Known" Prior Art 

2144.04	Legal Precedent as Source of Supporting 
Rationale  

2144.05	Obviousness of Ranges  

2144.06	Art Recognized Equivalence for the Same 
Purpose  

2144.07	Art Recognized Suitability for an Intended 
Purpose  

2144.08	Obviousness of Species When Prior Art 
Teaches Genus 

2144.09	Close Structural Similarity Between Chemical 
Compounds (Homologs, Analogues, Isomers) 

2145	Consideration of Applicant's Rebuttal 
Arguments 

2146	35 U.S.C. 103(c) 

2161	Three Separate Requirements for Specification 
Under 35 U.S.C. 112,  First Paragraph  

2162	Policy Underlying 35 U.S.C. 112, First 
Paragraph 

2163	The Written Description Requirement 

2163.01	Support for the Claimed Subject Matter in 
Disclosure 

2163.02	Standard for Determining Compliance With 
the Written Description Requirement 

2163.03	Typical Circumstances Where Adequate 
Written Description Issue Arises 

2163.04	Burden on the Examiner With Regard to the 
Written Description  Requirement 

2163.05	Changes to the Scope of Claims 

2163.06	Relationship of Written Description 
Requirement to New Matter 

2163.07	Amendments to Application Which Are 
Supported in the Original  Description 

2163.07(a)	Inherent Function, Theory, or Advantage 

2163.07(b)	Incorporation by Reference 

2164	The Enablement Requirement 

2164.01	Test of Enablement 

2164.01(a)	Undue Experimentation Factors 

2164.01(b)	How to Make the Claimed Invention 

2164.01(c)	How to Use the Claimed Invention  

2164.02	Working Example 

2164.03	Relationship of Predictability of the Art and the 
Enablement Requirement 

2164.04	Burden on the Examiner Under the Enablement 
Requirement 

2164.05	Determination of Enablement Based on 
Evidence As a Whole 

2164.05(a)	Specification Must Be Enabling as of the Filing 
Date 

2164.05(b)	Specification Must Be Enabling to Persons 
Skilled in the Art 

2164.06	Quantity of Experimentation 

2164.06(a)	Examples of Enablement Issues-Missing 
Information 

2164.06(b)	Examples of Enablement Issues - Chemical 
Cases 

2164.07	Relationship of Enablement Requirement to 
Utility  Requirement of 35 U.S.C. 101 

2164.08	Enablement Commensurate in  Scope With the 
Claims 

2164.08(a)	Single Means Claim 

2164.08(b)	Inoperative Subject Matter 

2164.08(c)	Critical Feature Not Claimed   

2165	The Best Mode Requirement 

2165.01	Considerations Relevant to Best Mode 

2165.02	Best Mode Requirement Compared to 
Enablement Requirement 

2165.03	Requirements for Rejection for Lack of Best 
Mode 

2165.04	Examples of Evidence of  Concealment  

2171	Two Separate Requirements for Claims Under 
35 U.S.C. 112, Second Paragraph  

2172	Subject Matter Which Applicants Regard as 
Their Invention 

2172.01	Unclaimed Essential Matter 

2173	Claims Must Particularly Point Out and 
Distinctly Claim the Invention 

2173.01	Claim Terminology 

2173.02	Clarity and Precision 

2173.03	Inconsistency Between Claim and 
Specification Disclosure or Prior  Art 

2173.04	Breadth Is Not Indefiniteness 

2173.05	Specific Topics Related to Issues Under 
35 U.S.C. 112, Second Paragraph 

2173.05(a)	New Terminology 

2173.05(b)	Relative Terminology 

2173.05(c)	Numerical Ranges and Amounts Limitations 

2173.05(d)	Exemplary Claim Language ("for example," 
"such as") 

2173.05(e)	Lack of Antecedent Basis 

2173.05(f)	Reference to Limitations in Another Claim 

2173.05(g)	Functional Limitations 

2173.05(h)	Alternative Limitations 

2173.05(i)	Negative Limitations 

2173.05(j)	Old Combination 

2173.05(k)	Aggregation 

2173.05(m)	Prolix 

2173.05(n)	Multiplicity 

2173.05(o)	Double Inclusion 

2173.05(p)	Claim Directed to Product-By- Process or 
Product and Process 

2173.05(q)	"Use" Claims 

2173.05(r)	Omnibus Claim 

2173.05(s)	Reference to Figures or Tables 

2173.05(t)	Chemical Formula 

2173.05(u)	Trademarks or Trade Names in a Claim 

2173.05(v)	Mere Function of Machine 

2173.06	Prior Art Rejection of Claim  Rejected as 
Indefinite 

2174	Relationship Between the Requirements of the 
First and Second Paragraphs of 35 U.S.C. 112 

2181	Identifying a 35 U.S.C. 112, Sixth  Paragraph 
Limitation 

2182	Scope of the Search and Identification of the 
Prior Art 

2183	Making a Prima Facie Case of   Equivalence 

2184	Determining Whether an Applicant  Has Met 
the Burden of Proving  Nonequivalence After a 
Prima Facie Case Is Made 

2185	Related Issues Under 35 U.S.C. 112, First or 
Second Paragraphs 

2186	Relationship to the Doctrine of  Equivalents 

2105	Patentable Subject Matter - Living 
Subject Matter [R-1]

The decision of the Supreme Court in Diamond v. 
Chakrabarty, 447 U.S. 303, 206 USPQ 193 (1980), held 
that microorganisms produced by genetic engineering are 
not excluded from patent protection by 35 U.S.C. 101. It is 
clear from the Supreme Court decision and opinion that the 
question of whether or not an invention embraces living 
matter is irrelevant to the issue of patentability. The test set 
down by the Court for patentable subject matter in this area 
is whether the living matter is the result of human interven-
tion. 

In view of this decision, the Office has issued these 
guidelines as to how  35 U.S.C. 101 will be interpreted.

The Supreme Court made the following points in the 
Chakrabarty opinion: 

1. "Guided by these canons of construction, this Court has 
read the term `manufacture' in ? 101 in accordance with its dic-
tionary definition to mean `the production of articles for use from 
raw materials prepared by giving to these materials new forms, 
qualities, properties, or combinations whether by hand labor or 
by machinery.'"

       

2. "In choosing such expansive terms as `manufacture' and 
`composition of matter,' modified by the comprehensive `any,' 
Congress plainly contemplated that the patent laws would be 
given wide scope."

       

3. "The Act embodied Jefferson's philosophy that `ingenuity 
should receive a liberal encouragement.' 5 Writings of Thomas 
Jefferson, at 75-76. See Graham v. John Deere Co., 383 U.S. 1, 
7-10 (1966). Subsequent patent statutes in 1836, 1870, and 1874 
employed this same broad language. In 1952, when the patent 
laws were recodified, Congress replaced the word `art' with `pro-
cess,' but otherwise left Jefferson's language intact. The Commit-
tee Reports accompanying the 1952 act inform us that Congress 
intended statutory subject matter to `include any thing under the 
sun that is made by man.' S. Rep. No. 1979, 82d Cong., 2d Sess., 
5 (1952)." 

       

4. "This is not to suggest that ? 101 has no limits or that it 
embraces every discovery. The laws of nature, physical phenom-
ena, and abstract ideas have been held not patentable." 

       

5. "Thus, a new mineral discovered in the earth or a new plant 
found in the wild is not patentable subject matter. Likewise, Ein-
stein could not patent his celebrated law that E=mc2 ; nor could 
Newton have patented the law of gravity." 

       

6. "His claim is not to a hitherto unknown natural phenome-
non, but to a nonnaturally occurring manufacture or composition 
of matter __ a product of human ingenuity `having a distinctive 
name, character [and] use.' " 

       

7. "Congress thus recognized that the relevant distinction was 
not between living and inanimate things, but between products of 
nature, whether living or not, and human-made inventions. Here, 
respondent's microorganism is the result of human ingenuity and 
research."

       

8. After reference to Funk Seed Co. & Kalo Co., 333 U.S.127 
(1948), "Here, by contrast, the patentee has produced a new bac-
terium with markedly different characteristics from any found in 
nature and one having the potential for significant utility. His dis-
covery is not nature's handiwork, but his own; accordingly it is 
patentable subject matter under ? 101." 

A review of the Court statements above as well as the 
whole Chakrabarty opinion reveals:

(A)	That the Court did not limit its decision to geneti-
cally engineered living organisms;

(B)	The Court enunciated a very broad interpretation 
of "manufacture" and "composition of matter" in 35 U.S.C. 
101 (Note esp. quotes 1, 2, and 3 above);

(C)	The Court set forth several tests for weighing 
whether patentable subject matter under 35 U.S.C. 101 is 
present stating (in quote 7 above) that:

The relevant distinction was not between living and inanimate 
things but between products of nature, whether living or not, and 
human-made inventions.

The tests set forth by the Court are (note especially the 
italicized portions):

(A)	"The laws of nature, physical phenomena and 
abstract ideas" are not patentable subject matter.

(B)	A "nonnaturally occurring manufacture or compo-
sition of matter - a product of human ingenuity -having 
a distinctive name, character, [and] use" is patentable sub-
ject matter.

(C)	"[A] new mineral discovered in the earth or a new 
plant found in the wild is not patentable subject matter. 
Likewise, Einstein could not patent his celebrated E=mc2; 
nor could Newton have patented the law of gravity. Such 
discoveries are `manifestations of . . . nature, free to all men 
and reserved exclusively to none.' '' 

(D)	"[T]he production of articles for use from raw 
materials prepared by giving to these materials new forms, 
qualities, properties, or combinations whether by hand 
labor or by machinery" [emphasis added] is a "manufac-
ture" under  35 U.S.C. 101.

In analyzing the history of the Plant Patent Act of 1930, 
the Court stated: "In enacting the Plant Patent Act, Con-
gress addressed both of these concerns [the concern that 
plants, even those artificially bred, were products of nature 
for purposes of the patent law and the concern that plants 
were thought not amenable to the written description]. It 
explained at length its belief that the work of the plant 
breeder `in aid of nature' was patentable invention. S. Rep. 
No. 315, 71st Cong., 2d Sess., 6-8 (1930); H.R. Rep. No. 
1129, 71st Cong., 2d Sess., 7-9 (1930)." 

The Office will decide the questions as to patentable 
subject matter under 35 U.S.C. 101 on a case-by-case basis 
following the tests set forth in Chakrabarty, e.g., that "a 
nonnaturally occurring manufacture or composition of mat-
ter" is patentable, etc. It is inappropriate to try to attempt to 
set forth here in advance the exact parameters to be fol-
lowed.

The standard of patentability has not and will not be low-
ered. The requirements of 35 U.S.C. 102 and 103 still 
apply. The tests outlined above simply mean that a rational 
basis will be present for any 35 U.S.C. 101 determination. 
In addition, the requirements of 35 U.S.C. 112 must also be 
met. In this regard, see  MPEP ? 608.01(p).

Following this analysis by the Supreme Court of the 
scope of 35 U.S.C. 101, **>the Federal Circuit held 
that patentable subject matter under 35 U.S.C.  101 
includes seeds and seed-grown plants, even though plant 
protection is also available under the Plant Patent Act (35 
U.S.C.  161 - 164) and the Plant Variety Protection Act (7 
U.S.C. 2321 et. seq.). Pioneer Hi-Bred International Inc. v. 
J.E.M. AG Supply Inc., 200 F.3d 1374, 53 USPQ2d 1440, 
1442-43 (Fed. Cir. 2000)(Title 35 and the Plant Variety Pro-
tection Act are not in conflict; there is simply a difference 
in the rights and obligations of each statute.). See also< Ex 
parte Hibberd, 227 USPQ 443 (Bd. Pat. App. & Inter. 
1985) >wherein< the Board held that plant subject matter 
may be the proper subject of a patent under 35 U.S.C. 101 
even though such subject matter may be protected under 
the Plant Patent Act ** or the Plant Variety Protection Act 
**.  >Following the reasoning in Chakrabarty, the Board of 
Patent Appeals and Interferences has also determined that 
animals are patentable subject matter under 35 U.S.C. 
101.<  In Ex parte Allen, 2 USPQ2d 1425 (Bd. Pat. App. & 
Inter. 1987), the Board decided that a polyploid Pacific 
coast oyster could have been the proper subject of a patent 
under 35 U.S.C. 101 if all the criteria for patentability were 
satisfied. Shortly after the Allen decision, the Commis-
sioner of Patents and Trademarks issued a notice (Animals 
- Patentability, 1077 O.G. 24, April 21, 1987) that the 
Patent and Trademark Office would now consider nonnatu-
rally occurring, nonhuman multicellular living organisms, 
including animals, to be patentable subject matter within 
the scope of  35 U.S.C. 101.

If the broadest reasonable interpretation of the claimed 
invention as a whole encompasses a human being, then a 
rejection under 35 U.S.C. 101 must be made indicating that 
the claimed invention is directed to nonstatutory subject 
matter. Furthermore, the claimed invention must be exam-
ined with regard to all issues pertinent to patentability, and 
any applicable rejections under 35 U.S.C. 102, 103, or 112 
must also be made.

2106	Patentable Subject Matter - 
Computer-Related Inventions [R-1]

I.	INTRODUCTION

These Examination Guidelines for Computer-Related 
Inventions ("Guidelines") are to assist Office personnel in 
the examination of applications drawn to computer-related 
inventions. "Computer-related inventions" include inven-
tions implemented in a computer and inventions employing 
computer-readable media.  The Guidelines are based on the 
Office's current understanding of the law and are believed 
to be fully consistent with binding precedent of the 
Supreme Court, the Federal Circuit and the Federal Cir-
cuit's predecessor courts.

These Guidelines do not constitute substantive rulemak-
ing and hence do not have the force and effect of law.  
These Guidelines have been designed to assist Office per-
sonnel in analyzing claimed subject matter for compliance 
with substantive law. Rejections will be based upon the 
substantive law and it is these rejections which are appeal-
able. Consequently, any failure by Office personnel to fol-
low the Guidelines is neither appealable nor petitionable.

The Guidelines alter the procedures Office personnel 
will follow when examining applications drawn to com-
puter-related inventions and are equally applicable to 
claimed inventions implemented in either hardware or soft-
ware. The Guidelines also clarify the Office's position on 
certain patentability standards related to this field of tech-
nology. Office personnel are to rely on these Guidelines in 
the event of any inconsistent treatment of issues between 
these Guidelines and any earlier provided guidance from 
the Office.

**

 >Office personnel should no longer rely on the Free-
man-Walter-Abele test to determine whether a claimed 
invention is directed to statutory subject matter. State Street 
Bank & Trust Co. v. Signature Financial Group Inc., 149 F. 
3d 1368, 1374, 47 USPQ2d 1596, 1601-02 (Fed. Cir. 1998) 
("After Diehr and Chakrabarty, the Freeman-Walter-Abele 
test has little, if any, applicability to determining the pres-
ence of statutory subject matter.").<

Office personnel have had difficulty in properly treating 
claims directed to methods of doing business.  Claims 
should not be categorized as methods of doing business.  
Instead, such claims should be treated like any other pro-
cess claims, pursuant to these Guidelines when relevant.  
See, e.g., >State Street, 149 F.3d at 1374-75, 47 USPQ2d at 
1602 (Fed. Cir. 1998);< In re Toma, 575 F.2d 872, 877-78, 
197 USPQ 852, 857 (CCPA 1978); In re Musgrave, 431 
F.2d 882, 893, 167 USPQ 280, 289-90 (CCPA 1970).  See 
also In re Schrader, 22 F.3d 290, 297-98, 30 USPQ2d 1455, 
1461-62 (Fed. Cir. 1994) (Newman, J., dissenting); Paine, 
Webber, Jackson & Curtis, Inc. v. Merrill Lynch, Pierce, 
Fenner & Smith, Inc., 564 F. Supp. 1358, 1368-69, 218 
USPQ 212, 220 (D. Del. 1983).

The appendix which appears at the end of this section 
includes a flow chart of the process Office personnel will 
follow in conducting examinations for computer-related 
inventions.

II.	DETERMINE WHAT APPLICANT HAS 
INVENTED AND IS SEEKING TO PATENT

It is essential that patent applicants obtain a prompt yet 
complete examination of their applications. Under the prin-
ciples of compact prosecution, each claim should be 
reviewed for compliance with every statutory requirement 
for patentability in the initial review of the application, 
even if one or more claims are found to be deficient with 
respect to some statutory requirement. Thus, Office person-
nel should state all reasons and bases for rejecting claims in 
the first Office action.  Deficiencies should be explained 
clearly, particularly when they serve as a basis for a rejec-
tion.  Whenever practicable, Office personnel should indi-
cate how rejections may be overcome and how problems 
may be resolved.  A failure to follow this approach can lead 
to unnecessary delays in the prosecution of the application.

Prior to focusing on specific statutory requirements, 
Office personnel must begin examination by determining 
what, precisely, the applicant has invented and is seeking to 
patent, and how the claims relate to and define that inven-
tion.  (As the courts have repeatedly reminded the Office:  
"The goal is to answer the question " `What did applicants 
invent?' " >In re< Abele, 684 F.2d *>902,< 907, 214 
USPQ *>682,< 687. Accord, e.g., Arrhythmia Research 
Tech. v. Corazonix Corp., 958 F.2d 1053, 1059, 22 USPQ2d 
1033, 1038 (Fed. Cir. 1992).)  Consequently, Office person-
nel will no longer begin examination by determining if a 
claim recites a "mathematical algorithm."  Rather they   
will review the complete specification, including the 
detailed description of the invention, any specific embodi-
ments that have been disclosed, the claims and any specific 
utilities that have been asserted for the invention.  

A.	Identify and Understand Any Practical Application 
Asserted for the Invention

**

>The claimed invention as a whole must accomplish a 
practical application.  That is, it must produce a "useful, 
concrete and tangible result." State Street, 149 F.3d at 1373, 
47 USPQ2d at 1601-02. The purpose of this requirement is 
to limit patent protection to inventions that possess a cer-
tain level of "real world" value, as opposed to subject mat-
ter that represents nothing more than an idea or concept, or 
is simply a starting point for future investigation or 
research (Brenner v. Manson, 383 U.S. 519, 528-36, 148 
USPQ 689, 693-96); In re Ziegler, 992, F.2d 1197, 1200-
03, 26 USPQ2d 1600, 1603-06 (Fed. Cir. 1993)). Accord-
ingly, a complete disclosure should contain some indication 
of the practical application for the claimed invention, i.e., 
why the applicant believes the claimed invention is useful. 

 Apart from the utility requirement of 35 U.S.C. 101, 
usefulness under the patent eligibility standard requires sig-
nificant functionality to be present to satisfy the useful 
result aspect of the practical application requirement. See 
Arrhythmia, 958 F.2d at 1057, 22 USPQ2d at 1036. Merely 
claiming nonfunctional descriptive material stored in a 
computer-readable medium does not make the invention 
eligible for patenting. For example, a claim directed to a 
word processing file stored on a disk may satisfy the utility 
requirement of 35 U.S.C. 101 since the information stored 
may have some "real world" value. However, the mere fact 
that the claim may satisfy the utility requirement of 
35 U.S.C.  101 does not mean that a useful result is 
achieved under the practical application requirement. The 
claimed invention as a whole must produce a "useful, con-
crete  and tangible" result to have a practical application.

 A process that consists solely of the manipulation of an 
abstract idea is  not concrete or tangible. See In re Warmer-
dam, 33 F.3d 1354, 1360, 31 USPQ2d 1754, 1759 (Fed. 
Cir. 1994). See also Schrader, 22 F.3d at 295, 30 USPQ2d 
at 1459. Office personnel have the burden to establish a 
prima facie case that the claimed invention as a whole is 
directed to solely an abstract idea or to manipulation of 
abstract ideas or does not produce a useful result. Only 
when the claim is devoid of any limitation to a practical 
application in the technological arts should it be rejected 
under 35 U.S.C. 101. Compare Musgrave, 431 F.2d at 893, 
167 USPQ at 289; In re Foster, 438 F.2d 1011, 1013, 169 
USPQ 99, 101 (CCPA 1971). Further, when such a rejec-
tion is made, Office personnel must expressly state how the 
language of the claims has been interpreted to support the 
rejection.<

The applicant is in the best position to explain why an 
invention is believed useful.  Office personnel should there-
fore focus their efforts on pointing out statements made in 
the specification that identify all practical applications for 
the invention.  Office personnel should rely on such state-
ments throughout the examination when assessing the 
invention for compliance with all statutory criteria.  An 
applicant may assert more than one practical application, 
but only one is necessary to satisfy the utility requirement.  
Office personnel should review the entire disclosure to 
determine the features necessary to accomplish at least one 
asserted practical application.

B.	Review the Detailed Disclosure and Specific 
Embodiments of the Invention to Determine What 
the Applicant Has Invented

The written description will provide the clearest expla-
nation of the applicant's invention, by exemplifying the 
invention, explaining how it relates to the prior art and 
explaining the relative significance of various features of 
the invention. Accordingly, Office personnel should begin 
their evaluation of a computer-related invention as follows:

- determine what the programmed computer does when 
it performs the processes dictated by the software (i.e., the 
functionality of the programmed computer) (Arrhythmia, 
958 F.2d at 1057, 22 USPQ at 1036, "It is of course true 
that a modern digital computer manipulates data, usually in 
binary form, by performing mathematical operations, such 
as addition, subtraction, multiplication, division, or bit 
shifting, on the data.  But this is only how the computer 
does what it does.  Of importance is the significance of the 
data and their manipulation in the real world, i.e., what the 
computer is doing.");

- determine how the computer is to be configured to 
provide that functionality (i.e., what elements constitute the 
programmed computer and how those elements are config-
ured and interrelated to provide the specified functionality); 
and

- if applicable, determine the relationship of the pro-
grammed computer to other subject matter outside the com-
puter that constitutes the invention (e.g., machines, devices, 
materials, or process steps other than those that are part of 
or performed by the programmed computer). (Many com-
puter-related inventions do not consist solely of a computer.  
Thus, Office personnel should identify those claimed ele-
ments of the computer-related invention that are not part of 
the programmed computer, and determine how those ele-
ments relate to the programmed computer.  Office person-
nel should look for specific information that explains the 
role of the programmed computer in the overall process or 
machine and how the programmed computer is to be inte-
grated with the other elements of the apparatus or used in 
the process.)

Patent applicants can assist the Office by preparing 
applications that clearly set forth these aspects of a com-
puter-related invention.

C.	Review the Claims

The claims define the property rights provided by 
a patent, and thus require careful scrutiny.  The goal 
of claim analysis is to identify the boundaries of the protec-
tion sought by the applicant and to understand how 
the claims relate to and define what the applicant has indi-
cated is the invention.  Office personnel must >first deter-
mine the scope of a claim by< thoroughly * >analyzing< 
the language of *>the< claim before determining if the 
claim complies with each statutory requirement for patent-
ability.  >See In re Hiniker Co., 150 F.3d 1362, 1369, 47 
USPQ2d 1523, 1529 (Fed. Cir. 1998) ("[T]he name of the 
game is the claim.").<

Office personnel should begin claim analysis by identi-
fying and evaluating each claim limitation. For processes, 
the claim limitations will define steps or acts to be per-
formed.  For products, the claim limitations will define dis-
crete physical structures >or materials<. Product claims are 
claims that are directed to either machines, manufactures or 
compositions of matter. The discrete physical structures 
>or materials< may be comprised of hardware or a combi-
nation of hardware and software.

Office personnel are to correlate each claim limitation to 
all portions of the disclosure that describe the claim limita-
tion. This is to be done in all cases, i.e., whether or not the 
claimed invention is defined using means or step plus func-
tion language. The correlation step will ensure that Office 
personnel correctly interpret each claim limitation.

The subject matter of a properly construed claim is 
defined by the terms that limit its scope.  It is this subject 
matter that must be examined. As a general matter, the 
grammar and intended meaning of terms used in a claim 
will dictate whether the language limits the claim scope.  
Language that suggests or makes optional but does not 
require steps to be performed or does not limit a claim to a 
particular structure does not limit the scope of a claim or 
claim limitation. The following are examples of language 
that may raise a question as to the limiting effect of the lan-
guage in a claim:

(A)	statements of intended use or field of use,

(B)	"adapted to" or  "adapted for" clauses,

(C)	"wherein" clauses, or

(D)	"whereby" clauses.

This list of examples is not intended to be exhaustive.

Office personnel must rely on the applicant's disclosure 
to properly determine the meaning of terms used in the 
claims. Markman v. Westview Instruments, 52 F.3d 967, 
980, 34 USPQ2d 1321, 1330 (Fed. Cir.) (en banc), aff'd,  
U.S. , 116 S. Ct. 1384 (1996).  An applicant is entitled to be 
his or her own lexicographer, and in many instances will 
provide an explicit definition for certain terms used in the 
claims.  Where an explicit definition is provided by the 
applicant for a term, that definition will control interpreta-
tion of the term as it is used in the claim.  >Toro Co. v. 
White Consolidated Industries Inc., 199 F.3d 1295, 1301, 
53 USPQ2d 1065, 1069 (Fed. Cir. 1999) (meaning of 
words used in a claim is not construed in a "lexicographic 
vacuum, but in the context of the specification and draw-
ings." ).<  Office personnel should determine if the original 
disclosure provides a definition consistent with any asser-
tions made by applicant. See, e.g., In re Paulsen, 30 F.3d 
1475, 1480, 31 USPQ2d 1671, 1674 (Fed. Cir. 1994) 
(inventor may define specific terms used to describe inven-
tion, but must do so "with reasonable clarity, deliberate-
ness, and precision" and, if done, must " `set out his 
uncommon definition in some manner within the patent 
disclosure' so as to give one of ordinary skill in the art 
notice of the change" in meaning) (quoting Intellicall, Inc. 
v. Phonometrics, Inc., 952 F.2d 1384, 1387-88, 21 USPQ2d 
1383, 1386 (Fed. Cir. 1992)).  >Any special meaning 
assigned to a term "must be sufficiently clear in the specifi-
cation that any departure from common usage would be so 
understood by a person of experience in the field of the 
invention." Multiform Desiccants Inc. v. Medzam Ltd., 133 
F.3d 1473, 1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998).<  
If an applicant does not define a term in the specification, 
that term will be given its "common meaning." Paulsen, at 
30 F. 3d 1480, 31 USPQ2d at 1674.

If the applicant asserts that a term has a meaning that 
conflicts with the term's art-accepted meaning, Office per-
sonnel should encourage the applicant to amend the claim 
to better reflect what applicant intends to claim as the 
invention.  If the application becomes a patent, it becomes 
prior art against subsequent applications.  Therefore, it is 
important for later search purposes to have the patentee 
employ commonly accepted terminology, particularly for 
searching text-searchable databases.

Office personnel must always remember to use the per-
spective of one of ordinary skill in the art.  Claims and dis-
closures are not to be evaluated in a vacuum. If elements of 
an invention are well known in the art, the applicant does 
not have to provide a disclosure that describes those ele-
ments. In such a case the elements will be construed as 
encompassing any and every art-recognized hardware or 
combination of hardware and software technique for imple-
menting the defined requisite functionalities.

Office personnel are to give claims their broadest rea-
sonable interpretation in light of the supporting disclosure. 
>In re Morris, 127 F.3d 1048, 1054-55, 44 USPQ2d 1023, 
1027-28 (Fed. Cir. 1997). Limitations appearing in the 
specification but not recited in the claim are not read into 
the claim. In re Prater, 415 F.2d 1393, 1404-05, 162 USPQ 
541, 550-551 (CCPA 1969).<  See *>also< In re Zletz, 893 
F.2d 319, 321-22, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) 
("During patent examination the pending claims must be 
interpreted as broadly as their terms reasonably allow. . . .  
The reason is simply that during patent prosecution when 
claims can be amended, ambiguities should be recognized, 
scope and breadth of language explored, and clarification 
imposed. . . .  An essential purpose of patent examination 
is to fashion claims that are precise, clear, correct, and 
unambiguous.  Only in this way can uncertainties of claim 
scope be removed, as much as possible, during the adminis-
trative process."). 

Where means plus function language is used to define 
the characteristics of a machine or manufacture invention, 
claim limitations must be interpreted to read on only the 
structures or materials disclosed in the specification and 
"equivalents thereof." (Two en banc decisions of the Fed-
eral Circuit have made clear that the Office is to interpret 
means plus function language according to 35 U.S.C. 112, 
sixth paragraph.  In the first, In re Donaldson, 16 F.3d 
1189, 1193, 29 USPQ2d 1845, 1848 (Fed. Cir. 1994), the 
court held:

The plain and unambiguous meaning of paragraph six is that 
one construing means-plus-function language in a claim must 
look to the specification and interpret that language in light of the 
corresponding structure, material, or acts described therein, and 
equivalents thereof, to the extent that the specification provides 
such disclosure.  Paragraph six does not state or even suggest that 
the PTO is exempt from this mandate, and there is no legislative 
history indicating that Congress intended that the PTO should be.  
Thus, this court must accept the plain and precise language of 
paragraph six.

Consistent with Donaldson, in the second decision, In re 
Alappat, 33 F.3d *>1526,< 1540, 31 USPQ2d *>1545,< 
1554 >(Fed. Cir. 1994) (in banc), the Federal Circuit held:

Given Alappat's disclosure, it was error for the Board major-
ity to interpret each of the means clauses in claim 15 so broadly 
as to "read on any and every means for performing the function" 
recited, as it said it was doing, and then to conclude that claim 15 
is nothing more than a process claim wherein each means clause 
represents a step in that process.  Contrary to suggestions by the 
Commissioner, this court's precedents do not support the Board's 
view that the particular apparatus claims at issue in this case may 
be viewed as nothing more than process claims.

Disclosure may be express, implicit or inherent.  Thus, at 
the outset, Office personnel must attempt to correlate 
claimed means to elements set forth in the written descrip-
tion.  The written description includes the >original< speci-
fication and the drawings.  Office personnel are to give the 
claimed means plus function limitations their broadest rea-
sonable interpretation consistent with all corresponding 
structures or materials described in the specification and 
their equivalents.  Further guidance in interpreting the 
scope of equivalents is provided in  MPEP ? 2181 through  
? 2186.

While it is appropriate to use the specification to deter-
mine what applicant intends a term to mean, a positive lim-
itation from the specification cannot be read into a claim 
that does not impose that limitation.  A broad interpretation 
of a claim by Office personnel will reduce the possibility 
that the claim, when issued, will be interpreted more 
broadly than is justified or intended.  An applicant can 
always amend a claim during prosecution to better reflect 
the intended scope of the claim.

Finally, when evaluating the scope of a claim, every lim-
itation in the claim must be considered. Office personnel 
may not dissect a claimed invention into discrete elements 
and then evaluate the elements in isolation.  Instead, the 
claim as a whole must be considered.  See, e.g., Diamond v. 
Diehr, 450 U.S. at 188-89, 209 USPQ at 9 ("In determining 
the eligibility of respondents' claimed process for patent 
protection under  101, their claims must be considered as a 
whole.  It is inappropriate to dissect the claims into old and 
new elements and then to ignore the presence of the old ele-
ments in the analysis.  This is particularly true in a process 
claim because a new combination of steps in a process may 
be patentable even though all the constituents of the combi-
nation were well known and in common use before the 
combination was made.").

III.	CONDUCT A THOROUGH SEARCH OF THE 
PRIOR ART

Prior to classifying the claimed invention under 
35 U.S.C. 101, Office personnel are expected to conduct a 
thorough search of the prior art.  Generally, a thorough 
search involves reviewing both U.S. and foreign patents 
and nonpatent literature. In many cases, the result of such a 
search will contribute to Office personnel's understanding 
of the invention. Both claimed and unclaimed aspects of the 
invention described in the specification should be searched 
if there is a reasonable expectation that the unclaimed 
aspects may be later claimed. A search must take into 
account any structure or material described in the specifica-
tion and its equivalents which correspond to the claimed 
means plus function limitation, in accordance with 
35 U.S.C. 112, sixth paragraph and  MPEP ? 2181 through  
? 2186.

IV.	DETERMINE WHETHER THE CLAIMED 
INVENTION COMPLIES WITH 35 U.S.C. 101

A.	Consider the Breadth of 35 U.S.C. 101 Under 
Controlling Law

As the Supreme Court has held, Congress chose the 
expansive language of 35 U.S.C. 101 so as to include "any-
thing under the sun that is made by man." Diamond v. 
Chakrabarty, 447 U.S. 303, 308-09, 206 USPQ 193, 197 
(1980).  Accordingly, section 101 of title 35, United States 
Code, provides:

Whoever invents or discovers any new and useful process, 
machine, manufacture, or composition of matter, or any new and 
useful improvement thereof, may obtain a patent therefor, subject 
to the conditions and requirements of this title.

In Diamond, 477 U.S. at 308-309, 206 USPQ at 197, the 
court stated:

In choosing such expansive terms as "manufacture" and "compo-
sition of matter," modified by the comprehensive "any," Con-
gress plainly contemplated that the patent laws would be given 
wide scope.  The relevant legislative history also supports a broad 
construction.  The Patent Act of 1793, authored by Thomas Jef-
ferson, defined statutory subject matter as "any new and useful 
art, machine, manufacture, or composition of matter, or any new 
or useful improvement [thereof]."  Act of Feb. 21, 1793, ch. 11,  
? 1, 1 Stat. 318.  The Act embodied Jefferson's philosophy that 
"ingenuity should receive a liberal encouragement." V Writings 
of Thomas Jefferson, at 75-76.  See Graham v.  John Deere Co., 
383 U.S. 1, 7-10 (148 USPQ 459, 462-464) (1966).  Subsequent 
patent statutes in 1836, 1870, and 1874 employed this same 
broad language.  In 1952, when the patent laws were recodified, 
Congress replaced the word "art" with "process," but otherwise 
left Jefferson's language intact.  The Committee Reports accom-
panying the 1952 Act inform us that Congress intended statutory 
subject matter to "include anything under the sun that is made by 
man."  S. Rep. No. 1979, 82d Cong., 2d Sess., 5 (1952); H.R. 
Rep. No. 1923, 82d Cong., 2d Sess., 6 (1952). [Footnote omitted]

This perspective has been embraced by the Federal Cir-
cuit:

The plain and unambiguous meaning of section 101 is that any 
new and useful process, machine, manufacture, or composition of 
matter, or any new and useful improvement thereof, may be pat-
ented if it meets the requirements for patentability set forth in 
Title 35, such as those found in sections 102, 103, and 112.  The 
use of the expansive term "any" in  section 101 represents Con-
gress's intent not to place any restrictions on the subject matter 
for which a patent may be obtained beyond those specifically 
recited in  section 101 and the other parts of Title 35. . . .  Thus, it 
is improper to read into section 101 limitations as to the subject 
matter that may be patented where the legislative history does not 
indicate that Congress clearly intended such limitations.  

Alappat, 33 F.3d at 1542, 31 USPQ2d at 1556.

As cast,  35 U.S.C. 101 defines four categories of inven-
tions that Congress deemed to be the appropriate subject 
matter of a patent; namely, processes, machines, manufac-
tures and compositions of matter.  The latter three catego-
ries define "things" while the first category defines 
"actions" (i.e., inventions that consist of a series of steps or 
acts to be performed). See 35 U.S.C. 100(b) ("The term 
`process' means process, art, or method, and includes a new 
use of a known process, machine, manufacture, composi-
tion of matter, or material.").

Federal courts have held that 35 U.S.C. 101 does have 
certain limits.  First, the phrase "anything under the sun that 
is made by man" is limited by the text of 35 U.S.C. 101, 
meaning that one may only patent something that is a 
machine, manufacture, composition of matter or a process.  
See, e.g., Alappat, 33 F.3d at 1542, 31 USPQ2d at 1556; ** 
Warmerdam, 33 F.3d *>at< 1358, 31 USPQ2d *>at< 1757 
(Fed. Cir. 1994).  Second, 35 U.S.C. 101 requires that the 
subject matter sought to be patented be a "useful" inven-
tion.  Accordingly, a complete definition of the scope of  35 
U.S.C. 101, reflecting Congressional intent, is that any new 
and useful process, machine, manufacture or composition 
of matter under the sun that is made by man is the proper 
subject matter of a patent.** 

The subject matter courts have found to be outside the 
four statutory categories of invention is limited to abstract 
ideas, laws of nature and natural phenomena.  While this is 
easily stated, determining whether an applicant is seeking 
to patent an abstract idea, a law of nature or a natural phe-
nomenon has proven to be challenging.  These three exclu-
sions recognize that subject matter that is not a practical 
application or use of an idea, a law of nature or a natural 
phenomenon is not patentable.  See, e.g., Rubber-Tip Pencil 
Co. v. Howard, 87 U.S. (20 Wall.) 498, 507 (1874) ("idea of 
itself is not patentable, but a new device by which it may be 
made practically useful is"); Mackay Radio & Telegraph 
Co. v.   Radio Corp. of America, 306 U.S. 86, 94, 40 USPQ 
199, 202 (1939) ("While a scientific truth, or the mathemat-
ical expression of it, is not patentable invention, a novel 
and useful structure created with the aid of knowledge of 
scientific truth may be."); Warmerdam,33 F.3d at 1360, 31 
USPQ2d at 1759 ("steps of `locating' a medial axis, and 
`creating' a bubble hierarchy . . . describe nothing more 
than the manipulation of basic mathematical constructs, the 
paradigmatic `abstract idea' ").

Courts have expressed a concern over "preemption" of 
ideas, laws of nature or natural phenomena.  The concern 
over preemption was expressed as early as 1852.  See Le 
Roy v. Tatham, 55 U.S. 156, 175 (1852) ("A principle, in 
the abstract, is a fundamental truth; an original cause; a 
motive; these cannot be patented, as no one can claim in 
either of them an exclusive right."); Funk Brothers Seed 
Co. v. Kalo Inoculant Co., 333 U.S. 127, 132, 76 USPQ 
280, 282 (1948) (combination of six species of bacteria 
held to be nonstatutory subject matter).  The concern over 
preemption serves to bolster and justify the prohibition 
against the patenting of such subject matter.  In fact, such 
concerns are only relevant to claiming a scientific truth or 
principle.  Thus, a claim to an "abstract idea" is nonstatu-
tory because it does not represent a practical application of 
the idea, not because it would preempt the idea.

B.	Classify the Claimed Invention as to Its Proper 
Statutory Category

To properly determine whether a claimed invention com-
plies with the statutory invention requirements of 35 U.S.C. 
101, Office personnel should classify each claim into one 
or more statutory or nonstatutory categories.  If the claim 
falls into a nonstatutory category, that should not preclude 
complete examination of the application for satisfaction of 
all other conditions of patentability.  This classification is 
only an initial finding at this point in the examination pro-
cess that will be again assessed after the examination for 
compliance with 35 U.S.C. 102, 103, and 112 is completed 
and before issuance of any Office action on the merits.

If the invention as set forth in the written description is 
statutory, but the claims define subject matter that is not, 
the deficiency can be corrected by an appropriate amend-
ment of the claims.  In such a case, Office personnel should 
reject the claims drawn to nonstatutory subject matter 
under  35 U.S.C. 101, but identify the features of the inven-
tion that would render the claimed subject matter statutory 
if recited in the claim.

1.	Nonstatutory Subject Matter

Claims to computer-related inventions that are clearly 
nonstatutory fall into the same general categories as non-
statutory claims in other arts, namely natural phenomena 
such as magnetism, and abstract ideas or laws of nature 
which constitute "descriptive material."  >Abstract ideas, 
Warmerdam, 33 F.3d at 1360, 31 USPQ2d at 1759, or the 
mere manipulation of abstract ideas, Schrader, 22 F.3d at 
292-93, 30 USPQ2d at 1457-58, are not patentable.<  
Descriptive material can be characterized as either "func-
tional descriptive material" or "nonfunctional descriptive 
material."  In this context, "functional descriptive material" 
consists of data structures and computer programs which 
impart functionality when **>employed as a computer 
component<. (The definition of "data structure" is "a phys-
ical or logical relationship among data elements, designed 
to support specific data manipulation functions."  The New 
IEEE Standard Dictionary of Electrical and Electronics 
Terms 308 (5th ed. 1993).)  "Nonfunctional descriptive 
material" includes but is not limited to music, literary 
works and a compilation or mere arrangement of data.

Both types of "descriptive material" are nonstatutory 
when claimed as descriptive material per se.  >Warmer-
dam, 33 F.3d at 1360, 31 USPQ2d at 1759.<  When func-
tional descriptive material is recorded on some computer-
readable medium it becomes structurally and functionally 
interrelated to the medium and will be statutory in most 
cases >since use of technology permits the function of the 
descriptive material to be realized<.  Compare In re Lowry, 
32 F.3d 1579, 1583-84, 32 USPQ2d 1031, 1035 (Fed. Cir. 
1994) (claim to data structure >stored on a computer read-
able medium< that increases computer efficiency held stat-
utory) and Warmerdam, 33 F.3d at 1360-61, 31 USPQ2d at 
1759 (claim to computer having specific memory held stat-
utory product-by-process claim) with Warmerdam, 33 F.3d 
at 1361, 31 USPQ2d at 1760 (claim to a data structure per 
se held nonstatutory).  When nonfunctional descriptive 
material is recorded on some computer-readable medium, it 
is not **>statutory since no requisite functionality is 
present to satisfy the practical application requirement<.  
Merely claiming nonfunctional descriptive material stored 
in a computer-readable medium does not make it statutory.  
Such a result would exalt form over substance. In re 
Sarkar, 588 F.2d 1330, 1333, 200 USPQ 132, 137 (CCPA 
1978)("[E]ach invention must be evaluated as claimed; yet 
semantogenic considerations preclude a determination 
based solely on words appearing in the claims.  In the final 
analysis under  101, the claimed invention, as a whole, 
must be evaluated for what it is.") (quoted with approval in 
Abele, 684 F.2d at 907, 214 USPQ at 687).  See also In re 
Johnson, 589 F.2d 1070, 1077, 200 USPQ 199, 206 (CCPA 
1978) ("form of the claim is often an exercise in drafting").  
Thus, nonstatutory music >is not a computer component 
and it< does not become statutory by merely recording it on 
a compact disk.  Protection for this type of work is pro-
vided under the copyright law.  

Claims to processes that do nothing more than solve 
mathematical problems or manipulate abstract ideas or con-
cepts are more complex to analyze and are addressed 
below.  **

>If the "acts" of a claimed process manipulate only 
numbers, abstract concepts or ideas, or signals representing 
any of the foregoing, the acts are not being applied to 
appropriate subject matter. Schrader, 22 F.3d at 294-95, 30 
USPQ2d at 1458-59.  Thus, a process consisting solely of 
mathematical operations, i.e., converting one set of num-
bers into another set of numbers, does not manipulate 
appropriate subject matter and thus cannot constitute a stat-
utory process.

In practical terms, claims define nonstatutory processes 
if they:

- consist solely of mathematical operations without 
some claimed practical application (i.e., executing a 
"mathematical algorithm"); or

- simply manipulate abstract ideas, e.g., a bid 
(Schrader, 22 F.3d at 293-94, 30 USPQ2d at 1458-59) 
or a bubble hierarchy (Warmerdam, 33 F.3d at 1360, 31 
USPQ2d at 1759), without some claimed practical 
application.

Cf. Alappat, 33 F.3d at 1543 n.19, 31 USPQ2d at 1556 
n.19 in which the Federal Circuit recognized the confusion:

The Supreme Court has not been clear . . . as to whether such 
subject matter is excluded from the scope of  101 because it rep-
resents laws of nature, natural phenomena, or abstract ideas. See 
Diehr, 450 U.S. at 186 (viewed mathematical algorithm as a law 
of nature); Gottschalk v. Benson, 409 U.S. 63, 71-72 (1972) 
(treated mathematical algorithm as an "idea").  The Supreme 
Court also has not been clear as to exactly what kind of mathe-
matical subject matter may not be patented.  The Supreme Court 
has used, among others, the terms "mathematical algorithm," 
"mathematical formula," and "mathematical equation" to 
describe types of mathematical subject matter not entitled to 
patent protection standing alone.  The Supreme Court has not set 
forth, however, any consistent or clear explanation of what it 
intended by such terms or how these terms are related, if at all.

Certain mathematical algorithms have been held to be 
nonstatutory because they represent a mathematical defini-
tion of a law of nature or a natural phenomenon.  For exam-
ple, a mathematical algorithm representing the formula E = 
mc2 is a "law of nature" - it defines a "fundamental scien-
tific truth" (i.e., the relationship between energy and mass).  
To comprehend how the law of nature relates to any object, 
one invariably has to perform certain steps (e.g., multiply-
ing a number representing the mass of an object by the 
square of a number representing the speed of light).  In 
such a case, a claimed process which consists solely of the 
steps that one must follow to solve the mathematical repre-
sentation of E = mc2 is indistinguishable from the law of 
nature and would "preempt" the law of nature.  A patent 
cannot be granted on such a process.<

(a)	Functional Descriptive Material: "Data 
Structures" Representing Descriptive Material 
Per Se or Computer Programs Representing 
Computer Listings Per Se

Data structures not claimed as embodied in computer-
readable media are descriptive material per se and are not 
statutory because they are ** >not capable of causing func-
tional change in the computer<.  See, e.g., Warmerdam, 
33 F.3d at 1361, 31 USPQ2d at 1760 (claim to a data struc-
ture per se held nonstatutory).  Such claimed data structures 
do not define any structural and functional interrelation-
ships between the data structure and other claimed aspects 
of the invention which permit the data structure's function-
ality to be realized.  In contrast, a claimed computer-read-
able medium encoded with a data structure defines 
structural and functional interrelationships between the 
data structure and the *>computer software and hardware 
components< which permit the data structure's functional-
ity to be realized, and is thus statutory.

Similarly, computer programs claimed as computer list-
ings per se, i.e., the descriptions or expressions of the pro-
grams, are not physical **>"things." They are neither 
computer components nor< statutory processes, as they 
are not "acts" being performed.  Such claimed computer 
programs do not define any structural and functional inter-
relationships between the computer program and other 
claimed **>elements of a computer< which permit the 
computer program's functionality to be realized.  In con-
trast, a claimed computer-readable medium encoded with a 
computer program >is a computer element which< defines 
structural and functional interrelationships between the 
computer program and the *>rest of the computer< which 
permit the computer program's functionality to be realized, 
and is thus statutory.  Accordingly, it is important to distin-
guish claims that define descriptive material per se from 
claims that define statutory inventions.

Computer programs are often recited as part of a claim.  
Office personnel should determine whether the computer 
program is being claimed as part of an otherwise statutory 
manufacture or machine.  In such a case, the claim remains 
statutory irrespective of the fact that a computer program is 
included in the claim.  The same result occurs when a com-
puter program is used in a computerized process where the 
computer executes the instructions set forth in the computer 
program.  Only when the claimed invention taken as a 
whole is directed to a mere program listing, i.e., to only its 
description or expression, is it descriptive material per se 
and hence nonstatutory.

Since a computer program is merely a set of instructions 
capable of being executed by a computer, the computer 
program itself is not a process and Office personnel should 
treat a claim for a computer program, without the com-
puter-readable medium needed to realize the computer pro-
gram's functionality, as nonstatutory functional descriptive 
material.  When a computer program is claimed in a pro-
cess where the computer is executing the computer pro-
gram's instructions, Office personnel should treat the claim 
as a process claim.  See Sections IV.B.2(b)-(e).  When a 
computer program is recited in conjunction with a physical 
structure, such as a computer memory, Office personnel 
should treat the claim as a product claim.  See Section 
IV.B.2(a).

(b)	Nonfunctional Descriptive Material

Descriptive material that cannot exhibit any functional 
interrelationship with the way in which computing pro-
cesses are performed does not constitute a statutory pro-
cess, machine, manufacture or composition of matter and 
should be rejected under 35 U.S.C. 101. Thus, Office per-
sonnel should consider the claimed invention as a whole to 
determine whether the necessary functional interrelation-
ship is provided.

Where certain types of descriptive material, such as 
music, literature, art, photographs and mere arrangements 
or compilations of facts or data, are merely stored so as to 
be read or outputted by a computer without creating any 
functional interrelationship, either as part of the stored data 
or as part of the computing processes performed by the 
computer, then such descriptive material alone does not 
impart functionality either to the data as so structured, or to 
the computer.  Such "descriptive material" is not a process, 
machine, manufacture or composition of matter.  (Data 
consists of facts, which become information when they are 
seen in context and convey meaning to people.  Computers 
process data without any understanding of what that data 
represents.  Computer Dictionary 210 (Microsoft Press, 2d 
ed. 1994).)

The policy that precludes the patenting of nonfunctional 
descriptive material would be easily frustrated if the same 
descriptive material could be patented when claimed as an 
article of manufacture.  For example, music is commonly 
sold to consumers in the format of a compact disc.  In such 
cases, the known compact disc acts as nothing more than a 
carrier for nonfunctional descriptive material.  The purely 
nonfunctional descriptive material cannot alone provide the 
practical application for the manufacture.

Office personnel should be prudent in applying the fore-
going guidance.  Nonfunctional descriptive material may 
be claimed in combination with other functional descriptive 
>multi-media< material on a computer-readable medium to 
provide the necessary functional and structural interrela-
tionship to satisfy the requirements of  35 U.S.C. 101.  The 
presence of the claimed nonfunctional descriptive material 
is not necessarily determinative of nonstatutory subject 
matter.  For example, a computer that recognizes a particu-
lar grouping of musical notes read from memory and upon 
recognizing that particular sequence, causes another 
defined series of notes to be played, defines a functional 
interrelationship among that data and the computing pro-
cesses performed when utilizing that data, and as such is 
statutory because it implements a statutory process.

(c)	Natural Phenomena Such as Electricity and 
Magnetism

Claims that recite nothing but the physical characteris-
tics of a form of energy, such as a frequency, voltage, or the 
strength of a magnetic field, define energy or magnetism, 
per se, and as such are nonstatutory natural phenomena. 
O'Reilly v. Morse, 56 U.S. (15 How.) at 112-114.  However, 
a >signal< claim directed to a practical application of 
**>electromagnetic< energy ** is statutory.    Id. at   114-
119.   

2.	Statutory Subject Matter

>For the purposes of a 35 U.S.C. 101 analysis, it is of lit-
tle relevance whether the claim is directed to a machine or a 
process. The legal principles are the same.  AT&T Corp. v. 
Excel Communications, Inc., 172 F.3d 1352, 1357, 50 
USPQ2d 1447, 1451 (Fed. Cir. 1999).<

(a)	Statutory Product Claims

Products may be either machines, manufactures of com-
positions of matter.

A machine is "a concrete thing, consisting of parts or of 
certain devices and combinations of devices." Burr v. 
Duryee, 68 U.S. (1 Wall.) 531, 570 (1863).

A manufacture is "the production of articles for use from 
raw or prepared materials by giving to these materials new 
forms, qualities, properties or combinations, whether by 
hand labor or by machinery." Diamond v. Chakrabarty, 447 
U.S. at 308, 206 USPQ at 196-97 (quoting American Fruit 
Growers, Inc. v. Brogdex Co., 283 U.S. 1, 11 (1931).

A composition of matter is "a composition[] of two or 
more substances [or] . . . a[] composite article[], whether 
[it] be the result of chemical union, or of mechanical mix-
ture, whether . . . [it]be [a] gas[], fluid[], powder[], or 
solid[]." Diamond v. Chakrabarty, 447 U.S. at 308, 206 
USPQ at 197 (quoting Shell Development Co. v. Watson, 
149 F. Supp. 279, 280, 113 USPQ 265, 266 (D.D.C. 1957), 
aff'd per curiam, 252 F.2d 861, 116 USPQ 428 (D.C. Cir. 
1958).

If a claim defines a useful machine or manufacture by 
identifying the physical structure of the machine or manu-
facture in terms of its hardware or hardware and software 
combination, it defines a statutory product.  See, e.g., 
Lowry, 32 F.3d at 1583, 32 USPQ2d at 1034-35; Warmer-
dam, 33 F.3d at 1361-62, 31 USPQ2d at 1760.

**

Office personnel must treat each claim as a whole.  The 
mere fact that a hardware element is recited in a claim does 
not necessarily limit the claim to a specific machine or 
manufacture. Cf. In re Iwahashi, 888 F.2d 1370, 1374-75, 
12 USPQ2d 1908, 1911-12 (Fed. Cir. 1989), cited with 
approval in Alappat, 33 F.3d at 1544 n.24, 31 USPQ2d at 
1558 n.24.  **

A claim limited to a * machine or manufacture, which 
has a practical application in the technological arts, is statu-
tory.  In most cases, a claim to a specific machine or manu-
facture will have a practical application in the technological 
arts.  >See Alappat, 33 F.3d at 1544, 31 USPQ2d at 1557 
("the claimed invention as a whole is directed to a combi-
nation of interrelated elements which combine to form a 
machine for converting discrete waveform data samples 
into anti-aliased pixel illumination intensity data to be dis-
played on a display means. This is not a disembodied math-
ematical concept which may be characterized as an 
`abstract idea,' but rather a specific machine to produce a 
useful, concrete, and tangible result."); and State Street, 149 
F.3d at 1373, 47 USPQ2d at 1601 ("the transformation of 
data, representing discrete dollar amounts, by a machine 
through a series of mathematical calculations into a final 
share price, constitutes a practical application of a mathe-
matical algorithm, formula, or calculation, because it pro-
duces `a useful, concrete and tangible result' -  a final 
share price momentarily fixed for recording and reporting 
purposes and even accepted and relied upon by regulatory 
authorities and in subsequent trades."). Also see AT&T, 172 
F.3d at 1358, 50 USPQ2d at 1452 (Claims drawn to a long-
distance telephone billing process containing mathematical 
algorithms were held patentable subject matter because the 
process used the algorithm to produce a useful, concrete, 
tangible result without preempting other uses of the mathe-
matical principle.).<

**

(b)	Statutory Process Claims

A claim that requires one or more acts to be performed 
defines a process.  However, not all processes are statutory 
under  35 U.S.C. 101.  >Schrader, 22 F.3d at 296, 30 
USPQ2d at 1460.<  To be statutory, a claimed computer-
related process must either:  (A) result in a physical trans-
formation outside the computer for which a practical appli-
cation in the technological arts is either disclosed in the 
specification or would have been known to a skilled artisan 
(discussed in i) below), or (B) be limited ** to a practical 
application within the technological arts (discussed in ii) 
below).  See Diamond v. Diehr, 450 U.S. at 183-84, 209 
USPQ at 6 (quoting Cochrane v. Deener, 94 U.S. 780, 787-
88 (1877)) ("A [statutory] process is a mode of treatment of 
certain materials to produce a given result.  It is an act, or a 
series of acts, performed upon the subject-matter to be 
transformed and reduced to a different state or thing. . . .  
The process requires that certain things should be done 
with certain substances, and in a certain order; but the tools 
to be used in doing this may be of secondary conse-
quence."). See also Alappat, 33 F.3d at 1543, 31 USPQ2d 
at 1556-57 (quoting Diamond v. Diehr, 450 U.S. at 192, 209 
USPQ at 10).  See also id. at 33 F.3d 1569, 31 USPQ2d at 
1578-79 (Newman, J., concurring) ("unpatentability of the 
principle does not defeat patentability of its practical appli-
cations") (citing O'Reilly v. Morse, 56 U.S. (15 How.) at 
114-19). ** If a physical transformation occurs outside the 
computer** >a< disclosure that permits a skilled artisan to 
practice the claimed invention, i.e., to put it to a practical 
use, is sufficient.  On the other hand, it is necessary to claim 
the practical application if there is no physical transforma-
tion or if the process merely manipulates concepts or con-
verts one set of numbers into another.

A claimed process is clearly statutory if it results in a 
physical transformation outside the computer, i.e., falls into 
one or both of the following specific categories ("safe har-
bors").

i)	Safe Harbors

-	Independent Physical Acts (Post-Computer 
Process Activity)

A process is statutory if it requires physical acts to be 
performed outside the computer independent of and follow-
ing the steps to be performed by a programmed computer, 
where those acts involve the manipulation of tangible phys-
ical objects and result in the object having a different phys-
ical attribute or structure. Diamond v. Diehr, 450 U.S. at 
187, 209 USPQ at 8. Thus, if a process claim includes one 
or more post-computer process steps that result in a physi-
cal transformation outside the computer (beyond merely 
conveying the direct result of the computer operation, ** 
the claim is clearly statutory.

Examples of this type of statutory process include the 
following:

- A method of curing rubber in a mold which relies 
upon updating process parameters, using a computer 
processor to determine a time period for curing the rub-
ber, using the computer processor to determine when 
the time period has been reached in the curing process 
and then opening the mold at that stage.

- A method of controlling a mechanical robot which 
relies upon storing data in a computer that represents 
various types of mechanical movements of the robot, 
using a computer processor to calculate positioning of 
the robot in relation to given tasks to be performed by 
the robot, and controlling the robot's movement and 
position based on the calculated position.

 > Examples of claimed processes that do not achieve a 
practical application include:

- step of "updating alarm limits" found to constitute 
changing the number value of a variable to represent the 
result of the calculation (Parker v. Flook, 437 U.S. 584, 
585, 198 USPQ 193, 195 (1978));

- final step of "equating" the process outputs to the val-
ues of the last set of process inputs found to constitute 
storing the result of calculations (Gelnovatch, 595 F.2d 
at 41 n.7, 201 USPQ at 145 n.7); and

- step of "transmitting electrical signals representing" 
the result of calculations (In re De Castelet, 562 F.2d 
1236, 1244, 195 USPQ 439, 446 (CCPA 1977) ("That 
the computer is instructed to transmit electrical signals, 
representing the results of its calculations, does not con-
stitute the type of `post solution activity' found in 
Flook, [437 U.S. 584, 198 USPQ 193 (1978)], and does 
not transform the claim into one for a process merely 
using an algorithm. The final transmitting step consti-
tutes nothing more than reading out the result of the cal-
culations.")).<

-	Manipulation of Data Representing Physical 
Objects or Activities (Pre-Computer Process 
Activity)

Another statutory process is one that requires the mea-
surements of physical objects or activities to be trans-
formed outside of the computer into computer data (In re 
Gelnovatch, 595 F.2d 32, 41 n.7, 201 USPQ 136, 145 n.7 
(CCPA 1979) (data-gathering step did not measure physical 
phenomenon)>; Arrhythmia, 958 F.2d at 1056, 22 USPQ2d 
at 1036<), where the data comprises signals corresponding 
to physical objects or activities external to the computer 
system, and where the process causes a physical transfor-
mation of the signals which are intangible representations 
of the physical objects or activities. Schrader, 22 F.3d at 
294, 30 USPQ2d at 1459 citing with approval Arrhythmia, 
958 F.2d at 1058-59, 22 USPQ2d at 1037-38; Abele, 684 
F.2d at 909, 214 USPQ at 688; In re Taner, 681 F.2d 787, 
790, 214 USPQ 678, 681 (CCPA 1982).

Examples of this type of claimed statutory process 
include the following:

- A method of using a computer processor to analyze 
electrical signals and data representative of human car-
diac activity by converting the signals to time segments, 
applying the time segments in reverse order to a high 
pass filter means, using the computer processor to 
determine the amplitude of the high pass filter's output, 
and using the computer processor to compare the value 
to a predetermined value.  In this example the data is an 
intangible representation of physical activity, i.e., 
human cardiac activity.  The transformation occurs 
when heart activity is measured and an electrical signal 
is produced.  This process has real world value in pre-
dicting vulnerability to ventricular tachycardia immedi-
ately after a heart attack.

- A method of using a computer processor to receive 
data representing Computerized Axial Tomography 
("CAT") scan images of a patient, performing a calcula-
tion to determine the difference between a local value at 
a data point and an average value of the data in a region 
surrounding the point, and displaying the difference as a 
gray scale for each point in the image, and displaying 
the resulting image.  In this example the data is an 
intangible representation of a physical object, i.e., por-
tions of the anatomy of a patient.  The transformation 
occurs when the condition of the human body is mea-
sured with X-rays and the X-rays are converted into 
electrical digital signals that represent the condition of 
the human body.  The real world value of the invention 
lies in creating a new CAT scan image of body tissue 
without the presence of bones.

- A method of using a computer processor to conduct 
seismic exploration, by imparting spherical seismic 
energy waves into the earth from a seismic source, gen-
erating a plurality of reflected signals in response to the 
seismic energy waves at a set of receiver positions in an 
array, and summing the reflection signals to produce a 
signal simulating the reflection response of the earth 
to the seismic energy.  In this example, the electrical 
signals processed by the computer represent reflected 
seismic energy. The transformation occurs by convert-
ing the spherical seismic energy waves into electrical 
signals which provide a geophysical representation of 
formations below the earth's surface. Geophysical 
exploration of formations below the surface of the earth 
has real world value.

>Examples of claimed processes that independently 
limit the claimed invention to safe harbor include:

- a method of conducting seismic exploration which 
requires generating and manipulating signals from seis-
mic energy waves before "summing" the values repre-
sented by the signals (Taner, 681 F.2d at 788, 214 
USPQ at 679); and

- a method of displaying X-ray attenuation data as a 
signed gray scale signal in a "field" using a particular 
algorithm, where the antecedent steps require generat-
ing the data using a particular machine (e.g., a computer 
tomography scanner). Abele, 684 F.2d at 908, 214 
USPQ at 687 ("The specification indicates that such 
attenuation data is available only when an X-ray beam 
is produced by a CAT scanner, passed through an 
object, and detected upon its exit. Only after these steps 
have been completed is the algorithm performed, and 
the resultant modified data displayed in the required 
format.").

Examples of claimed processes that do not limit the 
claimed invention to pre-computing safe harbor include:

- "perturbing" the values of a set of process inputs, 
where the subject matter "perturbed" was a number and 
the act of "perturbing" consists of substituting the 
numerical values of variables (Gelnovatch, 595 F.2d at 
41 n.7, 201 USPQ at 145 n.7 ("Appellants' claimed step 
of perturbing the values of a set of process inputs (step 
3), in addition to being a mathematical operation, 
appears to be a data-gathering step of the type we have 
held insufficient to change a nonstatutory method 
of calculation into a statutory process?. In 
this instance, the perturbed process inputs are not even 
measured values of physical phenomena, but are instead 
derived by numerically changing the values in the pre-
vious set of process inputs.")); and

- selecting a set of arbitrary measurement point values 
(Sarkar, 588 F.2d at 1331, 200 USPQ at 135).<

If a claim does not clearly fall into one or both of the 
safe harbors, the claim may still be statutory if it is limited 
** to a practical application in the technological arts.

ii)	Computer-Related Processes Limited to a 
Practical Application in the Technological Arts

There is always some form of physical transformation 
within a computer because a computer acts on signals and 
transforms them during its operation and changes the state 
of its components during the execution of a process.  Even 
though such a physical transformation occurs within a com-
puter, such activity is not determinative of whether the pro-
cess is statutory because such transformation alone does 
not distinguish a statutory computer process from a non-
statutory computer process. What is determinative is not 
how the computer performs the process, but what the com-
puter does to achieve a practical application.  See Arrhyth-
mia, 958 F.2d at 1057, 22 USPQ2d at 1036.

A process that merely manipulates an abstract idea or 
performs a purely mathematical algorithm is nonstatutory 
despite the fact that it might inherently have some useful-
ness.  In Sarkar, 588 F.2d at 1335, 200 USPQ at 139, the 
court explained why this approach must be followed:

No mathematical equation can be used, as a practical matter, 
without establishing and substituting values for the variables 
expressed therein.  Substitution of values dictated by the formula 
has thus been viewed as a form of mathematical step.  If the steps 
of gathering and substituting values were alone sufficient, every  
mathematical equation, formula, or algorithm having any practi-
cal use would be per se subject to patenting as a "process" under  
101.  Consideration of whether the substitution of specific values 
is enough to convert the disembodied ideas present in the formula 
into an embodiment of those ideas, or into an application of the 
formula, is foreclosed by the current state of the law.

For such subject matter to be statutory, the claimed pro-
cess must be limited to a practical application of the 
abstract idea or mathematical algorithm in the technologi-
cal arts.  See Alappat, 33 F.3d at 1543, 31 USPQ2d at 1556-
57 (quoting Diamond v. Diehr, 450 U.S. at 192, 209 USPQ 
at 10).  See also Alappat at 1569, 31 USPQ2d at 1578-79 
(Newman, J., concurring) ("unpatentability of the principle 
does not defeat patentability of its practical applications") 
(citing O'Reilly v. Morse, 56 U.S. (15 How.) at 114-19).  
>A claim is limited to a practical application when the 
method, as claimed, produces a concrete, tangible and use-
ful result; i.e., the method recites a step or act of producing 
something that is concrete, tangible and useful. See AT&T, 
172 F.3d at 1358, 50 USPQ2d at 1452. Likewise, a machine 
claim is statutory when the machine, as claimed, produces a 
concrete, tangible and useful result (as in State Street, 149 
F.3d at 1373, 47 USPQ2d at 1601) and/or when a specific 
machine is being claimed (as in Alappat, 33 F.3d at 1544, 
31 USPQ2d at 1557 (in banc).<  For example, a computer 
process that simply calculates a mathematical algorithm 
that models noise is nonstatutory. However, a claimed pro-
cess for digitally filtering noise employing the mathemati-
cal algorithm is statutory.

Examples of this type of claimed statutory process 
include the following:

- A computerized method of optimally controlling 
transfer, storage and retrieval of data between cache and 
hard disk storage devices such that the most frequently 
used data is readily available.

- A method of controlling parallel processors to accom-
plish multi-tasking of several computing tasks to maxi-
mize computing efficiency.  See, e.g., In re Bernhart, 
417 F.2d 1395, 1400, 163 USPQ 611,616 (CCPA 1969).

- A method of making a word processor by storing an 
executable word processing application program in a 
general purpose digital computer's memory, and exe-
cuting the stored program to impart word processing 
functionality to the general purpose digital computer by 
changing the state of the computer's arithmetic logic 
unit when program instructions of the word processing 
program are executed.

- A digital filtering process for removing noise from a 
digital signal comprising the steps of calculating a 
mathematical algorithm to produce a correction signal 
and subtracting the correction signal from the digital 
signal to remove the noise.

**

V.	EVALUATE APPLICATION FOR COMPLI-
ANCE WITH 35 U.S.C. 112

Office personnel should begin their evaluation of an 
application's compliance with 35 U.S.C. 112 by consider-
ing the requirements of 35 U.S.C. 112, second paragraph. 
The second paragraph contains two separate and distinct 
requirements: (A) that the claim(s) set forth the subject 
matter applicants regard as the invention, and (B) that the 
claim(s) particularly point out and distinctly claim the 
invention. An application will be deficient under 35 U.S.C. 
112, second paragraph when (A) evidence including admis-
sions, other than in the application as filed, shows applicant 
has stated that he or she regards the invention to be differ-
ent from what is claimed, or when (B) the scope of the 
claims is unclear.

After evaluation of the application for compliance with  
35 U.S.C. 112, second paragraph, Office personnel should 
then evaluate the application for compliance with the 
requirements of 35 U.S.C. 112, first paragraph. The first 
paragraph contains three separate and distinct require-
ments: 

(A)	adequate written description, 

(B)	enablement, and 

(C)	best mode. 

An application will be deficient under  35 U.S.C. 112, 
first paragraph when the written description is not adequate 
to identify what the applicant has invented, or when the dis-
closure does not enable one skilled in the art to make and 
use the invention as claimed without undue experimenta-
tion. Deficiencies related to disclosure of the best mode for 
carrying out the claimed invention are not usually encoun-
tered during examination of an application because evi-
dence to support such a deficiency is seldom in the record.  
>Fonar Corp. v. General Electric Co., 107 F.3d 1543, 
1548-49, 41 USPQ2d 1801, 1804 (Fed. Cir. 1997)<

If deficiencies are discovered with respect to 35 U.S.C. 
112, Office personnel must be careful to apply the appropri-
ate paragraph of  35 U.S.C. 112.

A.	Determine Whether the Claimed Invention 
Complies with 35 U.S.C. 112, Second Paragraph 
Requirements

1.	Claims Setting Forth the Subject Matter Appli-
cant Regards as Invention

Applicant's specification must conclude with claim(s) 
that set forth the subject matter which the applicant regards 
as the invention. The invention set forth in the claims is 
presumed to be that which applicant regards as the inven-
tion, unless applicant considers the invention to be some-
thing different from what has been claimed as shown by 
evidence, including admissions, outside the application as 
filed. An applicant may change what he or she regards as 
the invention during the prosecution of the application. 

2.	Claims Particularly Pointing Out and Distinctly 
Claiming the Invention

Office personnel shall determine whether the claims set 
out and circumscribe the invention with a reasonable 
degree of precision and particularity. In this regard, the def-
initeness of the language must be analyzed, not in a vac-
uum, but always in light of the teachings of the disclosure 
as it would be interpreted by one of ordinary skill in the art. 
Applicant's claims, interpreted in light of the disclosure, 
must reasonably apprise a person of ordinary skill in the art 
of the invention. However, the applicant need not explicitly 
recite in the claims every feature of the invention. For 
example, if an applicant indicates that the invention is a 
particular computer, the claims do not have to recite every 
element or feature of the computer. In fact, it is preferable 
for claims to be drafted in a form that emphasizes what the 
applicant has invented (i.e., what is new rather than old).  
>In re Dossel, 115 F.3d 942, 946, 42 USPQ2d 1881, 1884 
(Fed. Cir. 1997).<

A means plus function limitation is distinctly claimed if 
the description makes it clear that the means corresponds to 
well-defined structure of a computer or computer compo-
nent implemented in either hardware or software and its 
associated hardware platform.   >Atmel Corp. v. Informa-
tion Storage Devices Inc., 198 F.3d 1374, 1380, 53 
USPQ2d 1225, 1229 (Fed. Cir. 1999); B. Braun Medical, 
Inc. v. Abbott Labs., 124 F.3d 1419, 1424, 43 USPQ2d 
1896, 1899 (Fed. Cir. 1997).<  Such means may be defined 
as:

- a programmed computer with a particular functional-
ity implemented in hardware or hardware and software;

- a logic circuit or other component of a programmed 
computer that performs a series of specifically identi-
fied operations dictated by a computer program; or

- a computer memory encoded with executable instruc-
tions representing a computer program that can cause a 
computer to function in a particular fashion.

The scope of a "means" limitation is defined as the cor-
responding structure or material (e.g., a specific logic cir-
cuit) set forth in the written description and equivalents.  
See MPEP ? 2181 through ? 2186. Thus, a claim using 
means plus function limitations without corresponding dis-
closure of specific structures or materials that are not well-
known fails to particularly point out and distinctly claim 
the invention.  >Dossel, 115 F.3d at 946-47, 42 USPQ2d at 
1884-85.<  For example, if the applicant discloses only the 
functions to be performed and provides no express, implied 
or inherent disclosure of hardware or a combination of 
hardware and software that performs the functions, the 
application has not disclosed any "structure" which corre-
sponds to the claimed means. Office personnel should 
reject such claims under  35 U.S.C. 112, second paragraph. 
>B. Braun Medical, 124 F.3d at 1424, 43 USPQ2d at 
1899.<  The rejection shifts the burden to the applicant to 
describe at least one specific structure or material that cor-
responds to the claimed means in question, and to identify 
the precise location or locations in the specification where a 
description of at least one embodiment of that claimed 
means can be found. In contrast, if the corresponding struc-
ture is disclosed to be a memory or logic circuit that has 
been configured in some manner to perform that function 
(e.g., using a defined computer program), the application 
has disclosed "structure" which corresponds to the claimed 
means.

When a claim or part of a claim is defined in computer 
program code, whether in source or object code format, a 
person of skill in the art must be able to ascertain the metes 
and bounds of the claimed invention. In certain circum-
stances, as where self-documenting programming code is 
employed, use of programming language in a claim 
would be permissible because such program source code 
presents "sufficiently high-level language and descriptive 
identifiers" to make it universally understood to others in 
the art without the programmer having to insert any com-
ments. See Computer Dictionary 353 (Microsoft Press, 2ed. 
1994) for a definition of "self-documenting code." Appli-
cants should be encouraged to functionally define the steps 
the computer will perform rather than simply reciting 
source or object code instructions.

B.	Determine Whether the Claimed Invention 
Complies with 35 U.S.C. 112, First Paragraph 
Requirements

1.	Adequate Written Description

The satisfaction of the enablement requirement does not 
satisfy the written description requirement. See In re 
Barker, 559 F.2d 588, 591, 194 USPQ 470, 472 (CCPA 
1977)** (a specification may be sufficient to enable one 
skilled in the art to make and use the invention, but still fail 
to comply with the written description requirement). See 
also In re DiLeone, 436 F.2d 1404, 1405, 168 USPQ 592, 
593 (CCPA 1971). For the written description requirement, 
an applicant's specification must reasonably convey to 
those skilled in the art that the applicant was in possession 
of the claimed invention as of the date of invention. 
>Regents of the University of California v. Eli Lilly & Co., 
119 F.3d 1559, 1568, 43 USPQ2d 1398, 1405 (Fed. Cir. 
1997).<  The claimed invention subject matter need not be 
described literally, i.e., using the same terms, in order for 
the disclosure to satisfy the description requirement.

2.	Enabling Disclosure

An applicant's specification must enable a person skilled 
in the art to make and use the claimed invention without 
undue experimentation. The fact that experimentation is 
complex, however, will not make it undue if a person of 
skill in the art typically engages in such complex experi-
mentation. For a computer-related invention, the disclosure 
must enable a skilled artisan to configure the computer to 
possess the requisite functionality, and, where applicable, 
interrelate the computer with other elements to yield the 
claimed invention, without the exercise of undue experi-
mentation. The specification should disclose how to config-
ure a computer to possess the requisite functionality or how 
to integrate the programmed computer with other elements 
of the invention, unless a skilled artisan would know how 
to do so without such disclosure. See, e.g., >Dossel, 115 
F.3d at 946-47, 42 USPQ2d at 1884-85;< Northern Telecom 
v. Datapoint Corp., 908 F.2d 931, 941-43, 15 USPQ2d 
1321, 1328-30 (Fed. Cir.>1990<) ** (judgment of invalid-
ity reversed for clear error where expert testimony on both 
sides showed that a programmer of reasonable skill could 
write a satisfactory program with ordinary effort based on 
the disclosure); DeGeorge v. Bernier, 768 F.2d 1318, 1324, 
226 USPQ 758, 762-63 (Fed. Cir. 1985) (superseded by 
statute with respect to issues not relevant here) (invention 
was adequately disclosed for purposes of enablement even 
though all of the circuitry of a word processor was not dis-
closed, since the undisclosed circuitry was deemed incon-
sequential because it did not pertain to the claimed circuit); 
In re Phillips, 608 F.2d 879, 882-83, 203 USPQ 971, 975 
(CCPA 1979) (computerized method of generating printed 
architectural specifications dependent on use of glossary of 
predefined standard phrases and error-checking feature 
enabled by overall disclosure generally defining errors); In 
re Donohue, 550 F.2d 1269, 1271, 193 USPQ 136, 137 
(CCPA 1977) ("Employment of block diagrams and 
descriptions of their functions is not fatal under  35 U.S.C. 
112, first paragraph, providing the represented structure is 
conventional and can be determined without undue experi-
mentation."); In re Knowlton, 481 F.2d 1357, 1366-68, 178 
USPQ 486, 493-94 (CCPA 1973) (examiner's contention 
that a software invention needed a detailed description of 
all the circuitry in the complete hardware system reversed). 

For many computer-related inventions, it is not unusual 
for the claimed invention to involve more than one field of 
technology. For such inventions, the disclosure must satisfy 
the enablement standard for each aspect of the invention. 
See In re Naquin, 398 F.2d 863, 866, 158 USPQ 317, 319 
(CCPA 1968) ("When an invention, in its different aspects, 
involves distinct arts, that specification is adequate which 
enables the adepts of each art, those who have the best 
chance of being enabled, to carry out the aspect proper to 
their specialty."); Ex parte Zechnall, 194 USPQ 461, 461 
(Bd. App. 1973) ("appellants' disclosure must be held suffi-
cient if it would enable a person skilled in the electronic 
computer art, in cooperation with a person skilled in the 
fuel injection art, to make and use appellants' invention"). 
As such, the disclosure must teach a person skilled in each 
art how to make and use the relevant aspect of the invention 
without undue experimentation. For example, to enable a 
claim to a programmed computer that determines and dis-
plays the three-dimensional structure of a chemical com-
pound, the disclosure must

- enable a person skilled in the art of molecular model-
ing to understand and practice the underlying molecular 
modeling processes; and

- enable a person skilled in the art of computer pro-
gramming to create a program that directs a computer to 
create and display the image representing the three-
dimensional structure of the compound.

In other words, the disclosure corresponding to each 
aspect of the invention must be enabling to a person skilled 
in each respective art.

In many instances, an applicant will describe a pro-
grammed computer by outlining the significant elements of 
the programmed computer using a functional block dia-
gram. Office personnel should review the specification to 
ensure that along with the functional block diagram the dis-
closure provides information that adequately describes 
each "element" in hardware or hardware and its associated 
software and how such elements are interrelated. See In re 
Scarbrough, 500 F.2d 560, 565, 182 USPQ 298, 301-02 
(CCPA 1974) ("It is not enough that a person skilled in the 
art, by carrying on investigations along the line indicated in 
the instant application, and by a great amount of work 
eventually might find out how to make and use the instant 
invention. The statute requires the application itself to 
inform, not to direct others to find out for themselves (cita-
tion omitted)."); Knowlton, 481 F.2d at 1367, 178 USPQ at 
493 (disclosure must constitute more than a "sketchy expla-
nation of flow diagrams or a bare group of program listings 
together with a reference to a proprietary computer on 
which they might be run"). See also In re Gunn, 537 F.2d 
1123, 1127-28, 190 USPQ 402, 405 (CCPA 1976); In re 
Brandstadter, 484 F.2d 1395, 1406-07, 17 USPQ 286, 294 
(CCPA 1973); and In re Ghiron, 442 F.2d 985, 991, 169 
USPQ 723, 727-28 (CCPA 1971).

VI.	DETERMINE WHETHER THE CLAIMED 
INVENTION COMPLIES WITH 35 U.S.C. 102 
AND 103

As is the case for inventions in any field of technology, 
assessment of a claimed computer-related invention for 
compliance with 35 U.S.C. 102 and 103 begins with a com-
parison of the claimed subject matter to what is known in 
the prior art. If no differences are found between the 
claimed invention and the prior art, the claimed invention 
lacks novelty and is to be rejected by Office personnel 
under  35 U.S.C. 102. Once distinctions are identified 
between the claimed invention and the prior art, those dis-
tinctions must be assessed and resolved in light of the 
knowledge possessed by a person of ordinary skill in the 
art. Against this backdrop, one must determine whether the 
invention would have been obvious at the time the inven-
tion was made. If not, the claimed invention satisfies 
35 U.S.C. 103. Factors and considerations dictated by law 
governing 35 U.S.C. 103 apply without modification to 
computer-related inventions. 

If the difference between the prior art and the claimed 
invention is limited to descriptive material stored on or 
employed by a machine, Office personnel must determine 
whether the descriptive material is functional descriptive 
material or nonfunctional descriptive material, as described 
supra in sections IV.B.1(a) and IV. B.1(b). Functional 
descriptive material is a limitation in the claim and must be 
considered and addressed in assessing patentability under  
35 U.S.C. 103. Thus, a rejection of the claim as a whole 
under  35 U.S.C. 103 is inappropriate unless the functional 
descriptive material would have been suggested by the 
prior art. >In re Dembiczak, 175 F.3d 994, 1000, 50 
USPQ2d 1614, 1618 (Fed. Cir. 1999).<  Nonfunctional 
descriptive material cannot render nonobvious an invention 
that would have otherwise been obvious. Cf. In re Gulack, 
703 F.2d 1381, 1385, 217 USPQ 401, 404 (Fed. Cir. 1983) 
(when descriptive material is not functionally related to the 
substrate, the descriptive material will not distinguish the 
invention from the prior art in terms of patentability).

Common situations involving nonfunctional descriptive 
material are:

- a computer-readable storage medium that differs from 
the prior art solely with respect to nonfunctional 
descriptive material, such as music or a literary work, 
encoded on the medium,

- a computer that differs from the prior art solely with 
respect to nonfunctional descriptive material that can-
not alter how the machine functions (i.e., the descriptive 
material does not reconfigure the computer), or

- a process that differs from the prior art only with 
respect to nonfunctional descriptive material that can-
not alter how the process steps are to be performed to 
achieve the utility of the invention.

Thus, if the prior art suggests storing a song on a disk, 
merely choosing a particular song to store on the disk 
would be presumed to be well within the level of ordinary 
skill in the art at the time the invention was made. The dif-
ference between the prior art and the claimed invention is 
simply a rearrangement of nonfunctional descriptive mate-
rial.

VII.	Clearly Communicate Findings, Conclusions and 
Their Bases

Once Office personnel have concluded the above analy-
ses of the claimed invention under all the statutory provi-
sions, including 35 U.S.C. 101, 112, 102 and 103, they 
should review all the proposed rejections and their bases to 
confirm their correctness. Only then should any rejection 
be imposed in an Office action. The Office action should 
clearly communicate the findings, conclusions and reasons 
which support them.

2106.01	Computer Programming and 
35 U.S.C. 112, First Paragraph

The requirements for sufficient disclosure of inventions 
involving computer programming is the same as for all 
inventions sought to be patented. Namely, there must be an 
adequate written description, the original disclosure should 
be sufficiently enabling to allow one to make and use the 
invention as claimed, and there must be presentation of a 
best mode for carrying out the invention.

The following guidelines, while applicable to a wide 
range of arts, are intended to provide a guide for analyzing  
35 U.S.C. 112, first paragraph, issues in applications 
involving computer programs, software, firmware, or block 
diagram cases wherein one or more of the "block diagram" 
elements are at least partially comprised of a computer soft-
ware component. It should be recognized that sufficiency 
of disclosure issues in computer cases necessarily will 
require an inquiry into both the sufficiency of the disclosed 
hardware as well as the disclosed software due to the inter-
relationship and interdependence of computer hardware 
and software.

WRITTEN DESCRIPTION

The function of the description requirement is to ensure 
that the inventor had possession of, as of the filing date of 
the application relied on, the specific subject matter later 
claimed by him or her; how the specifica tion accomplishes 
this is not material. In re Herschler, 591 F.2d 693, 700-01, 
200 USPQ 711, 717 (CCPA 1979) and further reiterated in 
In re Kaslow, 707 F.2d 1366, 707 F.2d 1366, 217 USPQ 
1089 (Fed. Cir. 1983). See also MPEP ? 2163 -  ? 2163.04.

BEST MODE

The purpose of the best mode requirement is to "restrain 
inventors from applying for patents while at the same time 
concealing from the public the preferred embodiments of 
their inventions which they have in fact conceived," In re 
Gay, 309 F.2d 769, 772, 135 USPQ 311, 315 (CCPA 1962); 
"only evidence of concealment + (accidental or intentional) 
is to be considered [in judging the adequacy of a best mode 
disclosure]. That evidence, in order to result in affirmance 
of a best mode rejection, must tend to show that the quality 
of an applicant's best mode disclosure is so poor as to effec-
tively result in concealment." In re Sherwood, 613 F.2d 
809, 816-817, 204 USPQ 537, 544 (CCPA 1980). Also, see 
White Consol. Indus.  v. Vega Servo-Control Inc., 214 
USPQ 796, 824 (S.D. Mich. 1982), aff'd on related 
grounds, 713 F.2d 788, 218 USPQ 961 (Fed. Cir. 1983). 
See also  MPEP ? 2165 -  ? 2165.04.

There are two factual inquiries to be made in determin-
ing whether a specification satisfies the best mode require-
ment. First, there must be a subjective determination as to 
whether at the time the application was filed, the inventor 
knew of a best mode of practicing the invention.  Second, if 
the inventor had a best mode of practicing the invention, 
there must be an objective determination as to whether the 
best mode was disclosed in sufficient detail to allow one 
skilled in the art to practice it. Fonar Corp. v. General Elec-
tric Co., 107 F.3d 1543, 41 USPQ2d 1801, 1804 (Fed. Cir. 
1997); Chemcast Corp. v. Arco Industries, 913 F.2d 923, 
927-28, 16 USPQ2d 1033, 1036 (Fed. Cir. 1990).  "As a 
general rule, where software constitutes part of a best mode 
of carrying out an invention, description of such a best 
mode is satisfied by a disclosure of the functions of the 
software.  This is because, normally, writing code for such 
software is within the skill of the art, not requiring undue 
experimentation, once its functions have been disclosed. . . 
. [F]low charts or source code listings are not a requirement 
for adequately disclosing the functions of software." Fonar 
Corp., 107 F.3d at 1549,  41 USPQ2d at 1805 (citations 
omitted).

ENABLEMENT

When basing a rejection on the failure of the applicant's 
disclosure to meet the enablement provisions of the first 
paragraph of 35 U.S.C. 112, the examiner must establish on 
the record that he has a reasonable basis for questioning the 
adequacy of the disclosure to enable a person of ordinary 
skill in the art to make and use the claimed invention with-
out resorting to undue experimentation. See In re Brown, 
477 F.2d 946, 177 USPQ 691 (CCPA 1973); In re Ghiron, 
442 F.2d 985, 169 USPQ 723 (CCPA 1971). Once the 
examiner has advanced a reasonable basis for questioning 
the adequacy of the disclosure, it becomes incumbent on 
the applicant to rebut that challenge and factually demon-
strate that his or her application disclosure is in fact suffi-
cient. See In re Doyle, 482 F.2d 1385, 1392, 179 USPQ 
227, 232 (CCPA 1973); In re Scarbrough, 500 F.2d 560, 
566, 182 USPQ 298, 302 (CCPA 1974); In re Ghiron, 
supra. See also MPEP ? 2106, paragraph V.B.2 and ? 2164 
- ? 2164.08(c).

2106.02	Disclosure in Computer  
Programming Cases

To establish a reasonable basis for questioning the ade-
quacy of a disclosure, the examiner must present a factual 
analysis of a disclosure to show that a person skilled in the 
art would not be able to make and use the claimed inven-
tion without resorting to undue experimentation.

In computer applications, it is not unusual for the 
claimed invention to involve two areas of prior art or more 
than one technology, e.g., an appropriately programmed 
computer and an area of application of said computer. 
White Consol. Indus., 214 USPQ at 821.  In regard to the 
"skilled in the art" standard, in cases involving both the art 
of computer programming, and another technology, the 
examiner must recognize that the knowledge of persons 
skilled in both technologies is the appropriate criteria for 
determining sufficiency. See In re Naquin, 398 F.2d 863, 
158 USPQ 317 (CCPA 1968); In re Brown, 477 F.2d 946, 
177 USPQ 691 (CCPA 1973); and White Consol. Indus. v. 
Vega Servo-Control, Inc., 214 USPQ 796, 822 (S.D.Mich. 
1982), aff'd on related grounds, 713 F.2d 788, 218 USPQ 
961 (Fed. Cir. 1983  ).

In a typical computer application, system components 
are often represented in a "block diagram" format, i.e., a 
group of hollow rectangles representing the elements of the 
system, functionally labelled, and interconnected by lines. 
Such block diagram computer cases may be categorized 
into (A) systems which include but are more comprehen-
sive than a computer and (B) systems wherein the block 
elements are totally within the confines of a computer.

BLOCK ELEMENTS MORE COMPREHENSIVE 
THAN A COMPUTER

The first category of such block diagram cases involves 
systems which include a computer as well as other system 
hardware and/or software components. In order to meet his 
burden of establishing a reasonable basis for questioning 
the adequacy of such disclosure, the examiner should ini-
tiate a factual analysis of the system by focusing on each of 
the individual block element components. More specifi-
cally, such an inquiry should focus on the diverse functions 
attributed to each block element as well as the teachings in 
the specification as to how such a component could be 
implemented. If based on such an analysis, the examiner 
can reasonably contend that more than routine experimen-
tation would be required by one of ordinary skill in the art 
to implement such a component or components, that com-
ponent or components should specifically be challenged by 
the examiner as part of a 35 U.S.C. 112, first paragraph 
rejection. Additionally, the examiner should determine 
whether certain of the hardware or software components 
depicted as block elements are themselves complex assem-
blages which have widely differing characteristics and 
which must be precisely coordinated with other complex 
assemblages. Under such circumstances, a reasonable basis 
may exist for challenging such a functional block diagram 
form of disclosure. See In re Ghiron, 442 F.2d 985, 169 
USPQ 723 (CCPA 1971) and   In re Brown, supra. More-
over, even if the applicant has cited prior art patents or pub-
lications to demonstrate that particular block diagram 
hardware or software components are old, it should not 
always be considered as self-evident how such components 
are to be interconnected to function in a disclosed complex 
manner. See In re Scarbrough, 500 F.2d 560, 566, 182 
USPQ 298, 301 (CCPA 1974) and In re Forman, 463 F.2d 
1125, 1129, 175 USPQ 12, 16 (CCPA 1972). Furthermore, 
in complex systems including a digital computer, a micro-
processor, or a complex control unit as one of many block 
diagram elements, timing between various system elements 
may be of the essence and without a timing chart relating 
the timed sequences for each element, an unreasonable 
amount of work may be required to come up with the 
detailed relationships an applicant alleges that he has 
solved. See In re Scarbrough, 500 F.2d at 566, 182 USPQ 
at 302.

For example, in a block diagram disclosure of a complex 
claimed system which includes a microprocessor and other 
system components controlled by the microprocessor, a 
mere reference to a prior art, commercially available micro-
processor, without any description of the precise operations 
to be performed by the microprocessor, fails to disclose 
how such a microprocessor would be properly programmed 
to either perform any required calculations or to coordinate 
the other system components in the proper timed sequence 
to perform the functions disclosed and claimed. If, in such a 
system, a particular program is disclosed, such a program 
should be carefully reviewed to ensure that its scope is 
commensurate with the scope of the functions attributed to 
such a program in the claims. See In re Brown, 477 F.2d at 
951, 177 USPQ at 695. If the disclosure fails to disclose 
any program and if more than routine experimentation 
would be required of one skilled in the art to generate such 
a program, the examiner clearly would have a reasonable 
basis for challenging the sufficiency of such a disclosure. 
The amount of experimentation that is considered routine 
will vary depending on the facts and circumstances of indi-
vidual cases. No exact numerical standard has been fixed 
by the courts, but the "amount of required experimentation 
must, however, be reasonable." White Consol. Indus., 713 
F.2d at 791, 218 USPQ at 963. One court apparently found 
that the amount of experimentation involved was reason-
able where a skilled programmer was able to write a gen-
eral computer program, implementing an embodiment 
form, within 4 hours. Hirschfield v. Banner, 462 F. Supp. 
135, 142, 200 USPQ 276, 279 (D.D.C. 1978), aff'd, 615 
F.2d 1368 (D.C. Cir. 1986), cert. denied, 450 U.S. 994 
(1981).  On the other hand, another court found that, where 
the required period of experimentation for skilled program-
mers to develop a particular program would run to 1 to 2 
man years, this would be "a clearly unreasonable require-
ment" (White Consol. Indus., 713 F.2d at 791, 218  USPQ 
at 963).

BLOCK ELEMENTS WITHIN A COMPUTER

The second category of block diagram cases occurs most 
frequently in pure data processing applications where the 
combination of block elements is totally within the con-
fines of a computer, there being no interfacing with exter-
nal apparatus other than normal input/output devices. In 
some instances, it has been found that particular kinds of 
block diagram disclosures were sufficient to meet the 
enabling requirement of 35 U.S.C. 112, first paragraph. See 
In re Knowlton, 481 F.2d 1357, 178 USPQ 486 (CCPA 
1973), In re Comstock, 481 F.2d 905, 178 USPQ 616 
(CCPA 1973). Most significantly, however, in both the 
Comstock and Knowlton cases, the decisions turned on the 
appellants disclosure of (A) a reference to and reliance on 
an identified prior art computer system and (B) an opera-
tive computer program for the referenced prior art com-
puter system. Moreover, in Knowlton the disclosure was 
presented in such a detailed fashion that the individual pro-
gram's steps were specifically interrelated with the opera-
tive structural elements in the referenced prior art computer 
system. The court in Knowlton indicated that the disclosure 
did not merely consist of a sketchy explanation of flow dia-
grams or a bare group of program listings together with a 
reference to a proprietary computer in which they might be 
run. The disclosure was characterized as going into consid-
erable detail into explaining the interrelationships between 
the disclosed hardware and software elements. Under such 
circumstances, the Court considered the disclosure to be 
concise as well as full, clear, and exact to a sufficient 
degree to satisfy the literal language of  35 U.S.C. 112, first 
paragraph. It must be emphasized that because of the sig-
nificance of the program listing and the reference to and 
reliance on an identified prior art computer system, absent 
either of these items, a block element disclosure within the 
confines of a computer should be scrutinized in precisely 
the same manner as the first category of block diagram 
cases discussed above.

Regardless of whether a disclosure involves block ele-
ments more comprehensive than a computer or block ele-
ments totally within the confines of a computer, the 
examiner, when analyzing method claims, must recognize 
that the specification must be adequate to teach how to 
practice the claimed method. If such practice requires a par-
ticular apparatus, it is axiomatic that the application must 
therefore provide a sufficient disclosure of that apparatus if 
such is not already available. See In re Ghiron, 442 F.2d 
985, 991, 169 USPQ 723, 727 (CCPA 1971) and In re 
Gunn, 537 F.2d 1123, 1128, 190 USPQ 402, 406 (CCPA 
1976). When the examiner questions the adequacy of com-
puter system or computer programming disclosures, the 
examiner's reasons for finding the specification to be non-
enabling should be supported by the record as a whole. In 
this regard, it is also essential for the examiner to reason-
ably challenge evidence submitted by the applicant. For 
example, in In re Naquin, supra, affiant's statement unchal-
lenged by the examiner, that the average computer pro-
grammer was familiar with the subroutine necessary for 
performing the claimed process, was held to be a statement 
of fact which rendered the examiner's rejection baseless. In 
other words, unless the examiner presents a reasonable 
basis for challenging the disclosure in view of the record as 
a whole, a 35 U.S.C. 112, first paragraph rejection in a 
computer system or computer programming application 
will not be sustained on appeal. See In re Naquin, supra, 
and   In re Morehouse, 545 F.2d 162, 165-66, 192 USPQ 
29, 32 (CCPA 1976).

While no specific universally applicable rule exists for 
recognizing an insufficiently disclosed application involv-
ing computer programs, an examining guideline to gener-
ally follow is to challenge the sufficiency of such 
disclosures which fail to include either the computer pro-
gram itself or a reasonably detailed flowchart which delin-
eates the sequence of operations the program must perform. 
In programming applications software disclosure only 
includes a flowchart, as the complexity of functions and the 
generality of the individual components of the flowchart 
increase, the basis for challenging the sufficiency of such a 
flowchart becomes more reasonable because the likelihood 
of more than routine experimentation being required to 
generate a working program from such a flowchart also 
increases.

	As stated earlier, once an examiner has advanced a rea-
sonable basis or presented evidence to question the ade-
quacy of a computer system or computer programming 
disclosure, the applicant must show that his or her specifi-
cation would enable one of ordinary skill in the art to make 
and use the claimed invention without resorting to undue 
experimentation. In most cases, efforts to meet this burden 
involve submitting affidavits, referencing prior art patents 
or technical publications, arguments of counsel, or combi-
nations of these approaches.

AFFIDAVIT PRACTICE (37 CFR 1.132)

In computer cases, affidavits must be critically analyzed. 
Affidavit practice usually initially involves analyzing the 
skill level and/or qualifications of the affiant, which should 
be of the routineer in the art. When an affiant's skill level 
is higher than that required by the routineer for a particular 
application, an examiner may challenge the affidavit 
since it would not be made by a routineer in the art, and 
therefore would not be probative as to the amount of exper-
imentation required by a routineer in the art to implement 
the invention. An affiant having a skill level or qualifica-
tions above that of the routineer in the art would require 
less experimentation to implement the claimed invention 
than that for the routineer. Similarly, an affiant having a 
skill level or qualifications below that of the routineer in 
the art would require more experimentation to implement 
the claimed invention than that for the routineer in the art. 
In either situation, the standard of the routineer in the art 
would not have been met.

In computer systems or programming cases, the prob-
lems with a given affidavit, which relate to the sufficiency 
of disclosure issue, generally involve affiants submitting 
few facts to support their conclusions or opinions. Some 
affidavits may go so far as to present conclusions on the 
ultimate legal question of sufficiency. In re Brandstadter, 
484 F.2d 1395, 179 USPQ 286 (CCPA 1973) illustrates the 
extent of the inquiry into the factual basis underlying an 
affiant's conclusions or opinions. In Brandstadter, the 
invention concerned a stored program controller (com-
puter) programmed to control the storing, retrieving, and 
forwarding of messages in a communications system. The 
disclosure consisted of broadly defined block diagrams of 
the structure of the invention and no flowcharts or program 
listings of the programs of the controller. The Court quoted 
extensively from the Examiner's Office Actions and Exam-
iner's Answer in its opinion where it was apparent that the 
Examiner consistently argued that the disclosure was 
merely a broad system diagram in the form of labelled 
block diagrams along with statements of a myriad of 
desired results. Various affidavits were presented in which 
the affiants stated that all or some of the system circuit ele-
ments in the block diagrams were either well-known in the 
art or "could be constructed" by the skilled design engineer, 
that the controller was "capable of being programmed" to 
perform the stated functions or results desired, and that the 
routineer in the art "could design or construct or was able to 
program" the system. The Court did consider the affiants' 
statements as being some evidence on the ultimate legal 
question of enablement but concluded that the statements 
failed in their purpose since they recited conclusions or 
opinions with few facts to support or buttress these conclu-
sions. With reference to the lack of a disclosed computer 
program or even a flowchart of the program to control the 
message switching system, the record contained no evi-
dence as to the number of programmers needed, the number 
of man-hours and the level of skill of the programmers to 
produce the program required to practice the invention.

It should be noted also that it is not opinion evidence 
directed to the ultimate legal question of enablement, but 
rather factual evidence directed to the amount of time and 
effort and level of knowledge required for the practice of 
the invention from the disclosure alone which can be 
expected to rebut a prima facie case of nonenablement. See 
Hirschfield, 462 F. Supp. at 143, 200 USPQ at 281. It has 
also been held that where an inventor described the prob-
lem to be solved to an affiant, thus enabling the affiant to 
generate a computer program to solve the problem, such an 
affidavit failed to demonstrate that the application alone 
would have taught a person of ordinary skill in the art how 
to make and use the claimed invention.  See In re Brown, 
477 F.2d at 951, 177 USPQ at 695. The Court indicated that 
it was not factually established that the applicant did not 
convey to the affiant vital and additional information in 
their several meetings in addition to that set out in the 
application. Also of significance for an affidavit to be rele-
vant to the determination of enablement is that it must be 
probative of the level of skill of the routineer in the art as of 
the time the applicant filed his application. See In re Gunn, 
537 F.2d at 1128, 190 USPQ at 406. In this case, each of the 
affiants stated what was known at the time he executed the 
affidavit, and not what was known at the time the applicant 
filed his application.

REFERENCING PRIOR ART DOCUMENTS

Earlier, it had been discussed that citing in the specifica-
tion the commercial availability of an identified prior art 
computer system is very pertinent to the issue of enable-
ment. But in some cases, this approach may not be suffi-
cient to meet the applicant's burden. Merely citing in an 
affidavit extracts from technical publications in order to 
satisfy the enablement requirement is not sufficient if it is 
not made clear that a person skilled in the art would know 
which, or what parts, of the cited circuits could be used to 
construct the claimed device or how they could be intercon-
nected to act in combination to produce the required results. 
See In re Forman, 463 F.2d at 1129, 175 USPQ at 16. This 
analysis would appear to be less critical where the circuits 
comprising applicant's system are essentially standard com-
ponents comprising an identified prior art computer system 
and a standard device attached thereto.

Prior art patents are often relied on by applicants to show 
the state of the art for purposes of enablement. However, 
these patents must have an issue date earlier than the effec-
tive filing date of the application under consideration. See 
In re Budnick, 537 F.2d 535, 538, 190 USPQ 422, 424 
(CCPA 1976). An analogous point was made in In re Gunn, 
supra, where the court indicated that patents issued after 
the filing date of the applicant's application are not evi-
dence of subject matter known to any person skilled in the 
art since their subject matter may have been known only to 
the patentees and the Patent and Trademark Office.

Merely citing prior art patents to demonstrate that the 
challenged components are old may not be sufficient proof 
since, even if each of the enumerated devices or labelled 
blocks in a block diagram disclosure were old, per se, 
this would not make it self-evident how each would be 
interconnected to function in a disclosed complex combina-
tion manner. Therefore, the specification in effect must set 
forth the integration of the prior art; otherwise, it is likely 
that undue experimentation, or more than routine experi-
mentation would be required to implement the claimed 
invention. See In re Scarbrough, 560 F.2d at 565, 182 
USPQ at 301. The court also noted that any cited patents 
which are used by the applicant to demonstrate that particu-
lar box diagram hardware or software components are old 
must be analyzed as to whether such patents are germane to 
the instant invention and as to whether such components 
provide better detail of disclosure as to such components 
than an applicant's own disclosure. Also any patent or pub-
lication cited to provide evidence that a particular program-
ming technique is well-known in the programming art does 
not demonstrate that one of ordinary skill in the art could 
make and use correspondingly disclosed programming 
techniques unless both programming techniques are of 
approximately the same degree or complexity. See In re 
Knowlton, 500 F.2d 566, 572, 183 USPQ 33, 37 (CCPA 
1974).

ARGUMENTS OF COUNSEL

Arguments of counsel may be effective in establishing 
that an examiner has not properly met his or her burden or 
has otherwise erred in his or her position. In these situa-
tions, an examiner may have failed to set forth any basis for 
questioning the adequacy of the disclosure or may not have 
considered the whole specification, including the drawings 
and the written description. However, it must be empha-
sized that arguments of counsel alone cannot take the place 
of evidence in the record once an examiner has advanced a 
reasonable basis for questioning the disclosure. See In re 
Budnick, 537 F.2d at 538, 190 USPQ at 424; In re Schulze, 
346 F.2d 600, 145 USPQ 716 (CCPA 1965); and In re Cole, 
326 F.2d 769, 140 USPQ 230 (CCPA 1964). For example, 
in a case where the record consisted substantially of argu-
ments and opinions of applicant's attorney, the court indi-
cated that factual affidavits could have provided important 
evidence on the issue of enablement. See In re Knowlton, 
500 F.2d at 572, 183 USPQ at 37, and In re Wiseman, 596 
F.2d 1019, 201 USPQ 658 (CCPA 1979).

2107	General Principles Governing Utility 
Rejections

35 U.S.C. 101.  Inventions patentable

Whoever invents or discovers any new and useful process, machine, 
manufacture, or composition of matter, or any new and useful improve-
ment thereof may obtain a patent therefor, subject to the conditions and 
requirements of this title.

See  MPEP ? 706.03(a)(1) for guidelines for the exami-
nation of applications for compliance with the utility 
requirement of  35 U.S.C. 101.

The Office must examine each application to ensure 
compliance with the "useful invention" or utility require-
ment of 35 U.S.C. 101. In discharging this obligation, how-
ever, Office personnel must keep in mind several general 
principles that control application of the utility require-
ment. As interpreted by the Federal courts, 35 U.S.C. 101 
has two purposes. First, 35 U.S.C. 101 defines which cate-
gories of inventions are eligible for patent protection. An 
invention that is not a machine, an article of manufacture, a 
composition or a process cannot be patented. See Diamond 
v. Chakrabarty, 447 U.S. 303, 206 USPQ 193 (1980); Dia-
mond v. Diehr, 450 U.S. 175, 209 USPQ 1 (1981). Second,  
35 U.S.C. 101 serves to ensure that patents are granted on 
only those inventions that are "useful." This second pur-
pose has a Constitutional footing - Article I, Section 8 of 
the Constitution authorizes Congress to provide exclusive 
rights to inventors to promote the "useful arts." See Carl 
Zeiss Stiftung v. Renishaw PLC, 945 F.2d 1173, 20 USPQ2d 
1094 (Fed. Cir. 1991). Thus, to satisfy the requirements of  
35 U.S.C. 101, an applicant must claim an invention that is 
statutory subject matter and must show that the claimed 
invention is "useful" for some purpose either explicitly or 
implicitly. Application of this latter element of  35 U.S.C. 
101 is the focus of these guidelines.

Deficiencies under the "useful invention" requirement of  
35 U.S.C. 101 will arise in one of two forms. The first is 
where it is not apparent why the applicant believes the 
invention to be "useful." This can occur when an applicant 
fails to identify any specific utility for the invention or fails 
to disclose enough information about the invention to make 
its usefulness immediately apparent to those familiar with 
the technological field of the invention. Brenner v. Manson, 
383 U.S. 519, 148 USPQ 689 (1966); In re Ziegler, 992 
F.2d 1197, 26 USPQ2d 1600 (Fed. Cir. 1993). The second 
type of deficiency arises in the rare instance where an 
assertion of specific utility for the invention made by an 
applicant is not credible.

I.	"REAL WORLD VALUE" REQUIREMENT

To satisfy  35 U.S.C. 101, an invention must be "useful." 
Courts have recognized that the term "useful" used 
with reference to the utility requirement can be a difficult 
term to define. Brenner v. Manson, 383 U.S. 519, 529, 148 
USPQ 689, 693 (1966) (simple everyday word like "use-
ful" can be "pregnant with ambiguity when applied 
to the facts of life."). Where an applicant has set forth a 
specific utility, courts have been reluctant to uphold a rejec-
tion under  35 U.S.C. 101 solely on the basis that the appli-
cant's opinion as to the nature of the specific utility was 
inaccurate. For example, in Nelson v. Bowler, 626 F.2d 853, 
206 USPQ 881 (CCPA 1980), the court reversed a finding 
by the Office that the applicant had not set forth a "practi-
cal" utility under 35 U.S.C. 101 despite the fact that the 
applicant asserted that the composition was "useful" in a 
particular pharmaceutical application and provided evi-
dence to support that assertion. Courts have used the labels 
"practical utility" or "specific utility" to refer to this aspect 
of the "useful invention" requirement of 35 U.S.C. 101. 
The Court of Customs and Patent Appeals has stated:

Practical utility is a shorthand way of attributing "real-world" 
value to claimed subject matter. In other words, one skilled in the 
art can use a claimed discovery in a manner which provides some 
immediate benefit to the public.

Nelson v. Bowler, 626 F.2d 853, 856, 206 USPQ 881, 883 
(CCPA 1980).

Practical considerations require the Office to rely on the 
inventor's understanding of his or her invention in deter-
mining whether and in what regard an invention is believed 
to be "useful." Because of this, Office personnel should 
focus on and be receptive to specific assertions made by the 
applicant that an invention is "useful" for a particular rea-
son. Office personnel should distinguish between situations 
where an applicant has disclosed a specific use for or appli-
cation of the invention and situations where the applicant 
merely indicates that the invention may prove useful with-
out identifying with specificity why it is considered useful. 
For example, indicating that a compound may be useful in 
treating unspecified disorders, or that the compound has 
"useful biological" properties, would not be sufficient to 
define a specific utility for the compound. Contrast the situ-
ation where an applicant discloses a specific biological 
activity and reasonably correlates that activity to a disease 
condition. Assertions falling within the latter category are 
sufficient to identify a specific utility for the invention. 
Assertions that fall in the former category are insufficient 
to define a specific utility for the invention, especially if the 
assertion takes the form of a general statement that makes it 
clear that a "useful" invention may arise from what has 
been disclosed by the applicant. Knapp v. Anderson, 477 
F.2d 588, 177 USPQ 688 (CCPA 1973).

Some confusion can result when one attempts to label 
certain types of inventions as not being capable of having a 
specific utility based on the setting in which the invention 
is to be used. One example are inventions to be used in a 
research or laboratory setting. Many research tools such as 
gas chromatographs, screening assays, and nucleotide 
sequencing techniques have a clear, specific and unques-
tionable utility (e.g., they are useful in analyzing com-
pounds). An assessment that focuses on whether an 
invention is useful only in a research setting thus does not 
address whether the specific invention is in fact "useful" in 
a patent sense. Instead, Office personnel must distinguish 
between inventions that have a specifically identified utility 
and inventions whose specific utility requires further 
research to identify or reasonably confirm. Labels such as 
"research tool," "intermediate" or "for research purposes" 
are not helpful in determining if an applicant has identified 
a specific utility for the invention. 

Office personnel also must be careful not to interpret the 
phrase "immediate benefit to the public" or similar formu-
lations in other cases to mean that products or services 
based on the claimed invention must be "currently avail-
able" to the public in order to satisfy the utility require-
ment. See, e.g., Brenner v. Manson, 383 U.S. 519, 534-35, 
148 USPQ 689, 695 (1966). Rather, any reasonable use that 
an applicant has identified for the invention that can be 
viewed as providing a public benefit should be accepted as 
sufficient, at least with regard to defining a "specific" util-
ity. 

II.	WHOLLY INOPERATIVE INVENTIONS; 
"INCREDIBLE" UTILITY

An invention that is "inoperative" (i.e., it does not oper-
ate to produce the results claimed by the patent applicant) is 
not a "useful" invention in the meaning of the patent law.  
See, e.g., Newman v. Quigg, 877 F.2d 1575, 1581, 11 
USPQ2d 1340, 1345 (Fed. Cir. 1989); In re Harwood, 390 
F.2d 985, 989, 156 USPQ 673, 676 (CCPA 1968) ("An 
inoperative invention, of course, does not satisfy the 
requirement of 35 U.S.C. 101 that an invention be useful."). 
However, as the Federal Circuit has stated, "[t]o violate 
[35 U.S.C.] 101 the claimed device must be totally incapa-
ble of achieving a useful result." Brooktree Corp. v. 
Advanced Micro Devices, Inc., 977 F.2d 1555, 1571, 24 
USPQ2d 1401, 1412 (Fed. Cir. 1992) (emphasis added). 
See also E.I. du Pont De Nemours and Co. v. Berkley and 
Co., 620 F.2d 1247, 1260 n.17, 205 USPQ 1, 10 n.17 (8th 
Cir. 1980) ("A small degree of utility is sufficient . . . The 
claimed invention must only be capable of performing 
some beneficial function . . . An invention does not lack 
utility merely because the particular embodiment disclosed 
in the patent lacks perfection or performs crudely . . . A 
commercially successful product is not required . . . Nor is 
it essential that the invention accomplish all its intended 
functions . . . or operate under all conditions . . . partial suc-
cess being sufficient to demonstrate patentable utility . . . In 
short, the defense of non-utility cannot be sustained without 
proof of total incapacity." If an invention is only partially 
successful in achieving a useful result, a rejection of the 
claimed invention as a whole based on a lack of utility is 
not appropriate. See In re Brana, 51 F.3d 1560, 34 USPQ2d 
1436 (Fed. Cir. 1995); In re Gardner, 475 F.2d 1389, 177 
USPQ 396 (CCPA), reh'g denied, 480 F.2d 879 (CCPA 
1973); In re Marzocchi, 439 F.2d 220, 169 USPQ 367 
(CCPA 1971).

Situations where an invention is found to be "inopera-
tive" and therefore lacking in utility are rare, and rejections 
maintained solely on this ground by a Federal court even 
rarer. In many of these cases, the utility asserted by the 
applicant was thought to be "incredible in the light of the 
knowledge of the art, or factually misleading" when ini-
tially considered by the Office. In re Citron, 325 F.2d 248, 
253, 139 USPQ 516, 520 (CCPA 1963).  Other cases sug-
gest that on initial evaluation, the Office considered the 
asserted utility to be inconsistent with known scientific 
principles or "speculative at best" as to whether attributes 
of the invention necessary to impart the asserted utility 
were actually present in the invention. In re Sichert, 566 
F.2d 1154, 196 USPQ 209 (CCPA 1977). However cast, the 
underlying finding by the court in these cases was that, 
based on the factual record of the case, it was clear that the 
invention could and did not work as the inventor claimed it 
did. Indeed, the use of many labels to describe a single 
problem (e.g., an assertion regarding utility that is false) 
has led to some of the confusion that exists today with 
regard to a rejection based on the "utility" requirement. 
Examples of such cases include: an invention asserted to 
change the taste of food using a magnetic field (Fregeau v. 
Mossinghoff, 776 F.2d 1034, 227 USPQ 848 (Fed. Cir. 
1985)), a perpetual motion machine (Newman v. Quigg, 
877 F.2d 1575, 11 USPQ2d 1340 (Fed. Cir. 1989)), a flying 
machine operating on "flapping or flutter function" (In re 
Houghton, 433 F.2d 820, 167 USPQ 687 (CCPA 1970)), a 
method for increasing the energy output of fossil fuels upon 
combustion through exposure to a magnetic field (In re 
Ruskin, 354 F.2d 395, 148 USPQ 221 (CCPA 1966)), 
uncharacterized compositions for curing a wide array of 
cancers (In re Citron, 325 F.2d 248, 139 USPQ 516 (CCPA 
1963)), a method of controlling the aging process (In re Elt-
groth, 419 F.2d 918, 164 USPQ 221 (CCPA 1970)), and a 
method of restoring hair growth (In re Ferens, 417 F.2d 
1072, 163 USPQ 609 (CCPA 1969)). Thus, in view of the 
rare nature of such cases, Office personnel should not label 
an asserted utility "incredible," "speculative" or otherwise 
unless it is clear that a rejection based on "lack of utility" is 
proper.

III.	THERAPEUTIC OR PHARMACOLOGICAL 
UTILITY

Inventions asserted to have utility in the treatment of 
human or animal disorders are subject to the same legal 
requirements for utility as inventions in any other field of 
technology. In re Chilowsky, 229 F.2d 457, 461-2, 108 
USPQ 321, 325 (CCPA 1956) ("There appears to be no 
basis in the statutes or decisions for requiring any more 
conclusive evidence of operativeness in one type of case 
than another. The character and amount of evidence needed 
may vary, depending on whether the alleged operation 
described in the application appears to accord with or to 
contravene established scientific principles or to depend 
upon principles alleged but not generally recognized, but 
the degree of certainty as to the ultimate fact of operative-
ness or inoperativeness should be the same in all cases"); In 
re Gazave, 379 F.2d 973, 978, 154 USPQ 92, 96 (CCPA 
1967) ("Thus, in the usual case where the mode of opera-
tion alleged can be readily understood and conforms to the 
known laws of physics and chemistry, operativeness is not 
questioned, and no further evidence is required."). As such, 
pharmacological or therapeutic inventions that provide any 
"immediate benefit to the public" satisfy 35 U.S.C. 101. 
The utility being asserted in Nelson related to a compound 
with pharmacological utility. Nelson v. Bowler, 626 F.2d 
853, 856, 206 USPQ 881, 883 (CCPA 1980). Office per-
sonnel should rely on Nelson and other cases as providing 
general guidance when evaluating the utility of an inven-
tion that is based on any therapeutic, prophylactic, or phar-
macological activities of that invention. 

Courts have repeatedly found that the mere identification 
of a pharmacological activity of a compound that is rele-
vant to an asserted pharmacological use provides an 
"immediate benefit to the public" and thus satisfies the util-
ity requirement. As the Court of Customs and Patent 
Appeals held in Nelson v. Bowler:

Knowledge of the pharmacological activity of any compound is 
obviously beneficial to the public. It is inherently faster and eas-
ier to combat illnesses and alleviate symptoms when the medical 
profession is armed with an arsenal of chemicals having known 
pharmacological activities. Since it is crucial to provide research-
ers with an incentive to disclose pharmacological activities in as 
many compounds as possible, we conclude that adequate proof of 
any such activity constitutes a showing of practical utility.

Nelson v. Bowler, 626 F.2d 853, 856, 206 USPQ 881, 883 
(CCPA 1980).

In Nelson v. Bowler, the court addressed the practical 
utility requirement in the context of an interference pro-
ceeding. Bowler challenged the patentability of the inven-
tion claimed by Nelson on the basis that Nelson had failed 
to sufficiently and persuasively disclose in his application a 
practical utility for the invention. Nelson had developed 
and claimed a class of synthetic prostaglandins modeled on 
naturally occurring prostaglandins. Naturally occurring 
prostaglandins are bioactive compounds that, at the time of 
Nelson's application, had a recognized value in pharmacol-
ogy (e.g., the stimulation of uterine smooth muscle which 
resulted in labor induction or abortion, the ability to raise or 
lower blood pressure, etc.). To support the utility he identi-
fied in his disclosure, Nelson included in his application the 
results of tests demonstrating the bioactivity of his new 
substituted prostaglandins relative to the bioactivity of nat-
urally occurring prostaglandins. The court concluded that 
Nelson had satisfied the practical utility requirement in 
identifying the synthetic prostaglandins as pharmacologi-
cally active compounds. In reaching this conclusion, the 
court considered and rejected arguments advanced by 
Bowler that attacked the evidentiary basis for Nelson's 
assertions that the compounds were pharmacologically 
active.

In In re Jolles, 628 F.2d 1322, 206 USPQ 885 (CCPA 
1980), an inventor claimed protection for pharmaceutical 
compositions for treating leukemia. The active ingredient 
in the compositions was a structural analog to a known 
anticancer agent. The applicant provided evidence showing 
that the claimed analogs had the same general pharmaceuti-
cal activity as the known anticancer agents. The court 
reversed the Board's finding that the asserted pharmaceuti-
cal utility was "incredible," pointing to the evidence that 
showed the relevant pharmacological activity.

In Cross v. Iizuka, 753 F.2d 1040, 224 USPQ 739 (Fed. 
Cir. 1985), the Federal Circuit affirmed a finding by the 
Board of Patent Appeals and Interferences that a pharmaco-
logical utility had been disclosed in the application of one 
party to an interference proceeding. The invention that was 
the subject of the interference count was a chemical com-
pound used for treating blood disorders. Cross had chal-
lenged the evidence in Iizuka's specification that supported 
the claimed utility. However, the Federal Circuit relied 
extensively on Nelson v. Bowler in finding that Iizuka's 
application had sufficiently disclosed a pharmacological 
utility for the compounds. It distinguished the case from 
cases where only a generalized "nebulous" expression, 
such as "biological properties," had been disclosed in a 
specification. Such statements, the court held, "convey lit-
tle explicit indication regarding the utility of a compound." 
Cross, 753 F.2d at 1048, 224 USPQ at 745 (citing In re 
Kirk, 376 F.2d 936, 941, 153 USPQ 48, 52 (CCPA 1967)).

Similarly, courts have found utility for therapeutic 
inventions despite the fact that an applicant is at a very 
early stage in the development of a pharmaceutical product 
or therapeutic regimen based on a claimed pharmacological 
or bioactive compound or composition. The Federal Cir-
cuit, in Cross v. Iizuka, 753 F.2d 1040, 1051, 224 USPQ 
739, 747-48 (Fed. Cir. 1985), commented on the signifi-
cance of data from in vitro testing that showed pharmaco-
logical activity:

We perceive no insurmountable difficulty, under appropriate cir-
cumstances, in finding that the first link in the screening chain, in 
vitro testing, may establish a practical utility for the compound in 
question. Successful in  vitro testing will marshal resources and 
direct the expenditure of effort to further in vivo testing of the 
most potent compounds, thereby providing an immediate benefit 
to the public, analogous to the benefit provided by the showing of 
an in vivo utility.

Recently, the Federal Circuit reiterated that therapeutic 
utility sufficient under the patent laws is not to be confused 
with the requirements of the FDA with regard to safety and 
efficacy of drugs to marketed in the United States.

FDA approval, however, is not a prerequisite for finding a com-
pound useful within the meaning of the patent laws. Scott [v. 
Finney], 34 F.3d 1058, 1063, 32 USPQ2d 1115, 1120 [(Fed.Cir. 
1994)]. Usefulness in patent law, and in particular in the context 
of pharmaceutical inventions, necessarily includes the expecta-
tion of further research and development. The stage at which an 
invention in this field becomes useful is well before it is ready to 
be administered to humans. Were we to require Phase II testing in 
order to prove utility, the associated costs would prevent many 
companies from obtaining patent protection on promising new 
inventions, thereby eliminating an  incentive to pursue, through 
research and development, potential cures in many crucial areas 
such as the treatment of cancer.

In re Brana, 51 F.3d 1560, 34 USPQ2d 1436 (Fed. Cir. 
1995). Accordingly, Office personnel should not construe  
35 U.S.C. 101, under the logic of "practical" utility or oth-
erwise, to require that an applicant demonstrate that a thera-
peutic agent based on a claimed invention is a safe or fully 
effective drug for humans. See, e.g., In re Sichert, 566 F.2d 
1154, 196 USPQ 209 (CCPA 1977); In re Hartop, 311 F.2d 
249, 135 USPQ 419 (CCPA 1962); In re Anthony, 414 F.2d 
1383, 162 USPQ 594 (CCPA 1969); In re Watson, 517 F.2d 
465, 186 USPQ 11 (CCPA 1975).

These general principles are equally applicable to situa-
tions where an applicant has claimed a process for treating 
a human or animal disorder. In such cases, the asserted util-
ity is usually clear - the invention is asserted to be useful 
in treating the particular disorder. If the asserted utility is 
credible, there is no basis to challenge such a claim on the 
basis that it lacks utility under 35 U.S.C. 101.

IV.	RELATIONSHIP BETWEEN 35 U.S.C. 112, 
FIRST PARAGRAPH, AND 35 U.S.C. 101

A deficiency under 35 U.S.C. 101 also creates a defi-
ciency under 35 U.S.C. 112, first paragraph. See In re 
Brana, 51 F.3d 1560, 34 USPQ2d 1436 (Fed. Cir. 1995); In 
re Jolles, 628 F.2d 1322, 1326 n.10, 206 USPQ 885, 889 
n.11 (CCPA 1980); In re Fouche, 439 F.2d 1237, 1243, 169 
USPQ 429, 434 (CCPA 1971) ("If such compositions are in 
fact useless, appellant's specification cannot have taught 
how to use them."). Courts have also cast the 35 U.S.C. 
101/35 U.S.C. 112 relationship such that 35 U.S.C. 112 
presupposes compliance with 35 U.S.C. 101 compliance. 
See In re Ziegler, 992 F.2d 1197, 1200-1201, 26 USPQ2d 
1600, 1603 (Fed. Cir. 1993) ("The how to use prong of sec-
tion 112 incorporates as a matter of law the requirement of  
35 U.S.C. 101 that the specification disclose as a matter of 
fact a practical utility for the invention. ... If the application 
fails as a matter of fact to satisfy 35 U.S.C. ? 101, then the 
application also fails as a matter of law to enable one of 
ordinary skill in the art to use the invention under 35 U.S.C. 
? 112."); In re Kirk, 376 F.2d 936, 942, 153 USPQ 48, 53 
(CCPA 1967) ("Necessarily, compliance with ? 112 
requires a description of how to use presently useful inven-
tions, otherwise an applicant would anomalously be 
required to teach how to use a useless invention."). For 
example, the Federal Circuit recently noted, "[o]bviously, if 
a claimed invention does not have utility, the specification 
cannot enable one to use it." In re Brana, 51 F.3d 1560, 34 
USPQ2d 1436 (Fed. Cir. 1995). As such, a rejection prop-
erly imposed under 35 U.S.C. 101 should be accompanied 
with a rejection under 35 U.S.C. 112, first paragraph. It is 
equally clear that a rejection based on "lack of utility," 
whether grounded upon 35 U.S.C. 101 or 35 U.S.C. 112, 
first paragraph, rests on the same basis (i.e., the asserted 
utility is not credible). To avoid confusion, any rejection 
that is imposed on the basis of 35 U.S.C. 101 should be 
accompanied by a rejection based on 35 U.S.C. 112, first 
paragraph. The 35 U.S.C. 112, first paragraph, rejection 
should be set out as a separate rejection that incorporates by 
reference the factual basis and conclusions set forth in the  
35 U.S.C. 101 rejection. The 35 U.S.C. 112, first para-
graph, rejection should indicate that because the invention 
as claimed does not have utility, a person skilled in the art 
would not be able to use the invention as claimed, and as 
such, the claim is defective under  35 U.S.C. 112, first para-
graph. A  35 U.S.C. 112, first paragraph, rejection should 
not be imposed or maintained unless an appropriate basis 
exists for imposing a rejection under 35 U.S.C. 101. In 
other words, Office personnel should not impose a 35 
U.S.C. 112, first paragraph, rejection grounded on a "lack 
of utility" basis unless a 35 U.S.C. 101 rejection is proper. 
In particular, the factual showing needed to impose a rejec-
tion under 35 U.S.C. 101 must be provided if a rejection 
under 35 U.S.C. 112, first paragraph, is to be imposed on 
"lack of utility" grounds.

It is important to recognize that 35 U.S.C. 112, first para-
graph, addresses matters other than those related to the 
question of whether or not an invention lacks utility. These 
matters include whether the claims are fully supported by 
the disclosure (In re Vaeck, 947 F.2d 488, 495, 20 USPQ2d 
1438, 1444 (Fed. Cir. 1991)), whether the applicant has 
provided an enabling disclosure of the claimed subject mat-
ter (In re Wright, 999 F.2d 1557, 1561-1562, 27 USPQ2d 
1510, 1513 (Fed. Cir. 1993)), whether the applicant has 
provided an adequate written description of the invention 
and whether the applicant has disclosed the best mode of 
practicing the claimed invention (Chemcast Corp. v. Arco 
Indus. Corp., 913 F.2d 923, 927-928, 16 USPQ2d 1033, 
1036-1037 (Fed. Cir. 1990). See also Transco Products Inc. 
v. Performance Contracting Inc., 38 F.3d 551, 32 USPQ2d 
1077 (Fed. Cir. 1994); Glaxo Inc. v. Novopharm Ltd. 52 
F.3d 1043, 34 USPQ2d 1565 (Fed. Cir. 1995)). The fact 
that an applicant has disclosed a specific utility for an 
invention and provided a credible basis supporting that spe-
cific utility does not provide a basis for concluding that the 
claims comply with all the requirements of 35 U.S.C. 112, 
first paragraph. For example, if an applicant has claimed a 
process of treating a certain disease condition with a certain 
compound and provided a credible basis for asserting that 
the compound is useful in that regard, but to actually prac-
tice the invention as claimed a person skilled in the relevant 
art would have to engage in an undue amount of experi-
mentation, the claim may be defective under 35 U.S.C. 112, 
but not 35 U.S.C. 101. To avoid confusion during examina-
tion, any rejection under 35 U.S.C. 112, first paragraph, 
based on grounds other than "lack of utility" should be 
imposed separately from any rejection imposed due to 
"lack of utility" under 35 U.S.C. 101 and 35 U.S.C. 112, 
first paragraph.

2107.01	Procedural Considerations Related 
to Rejections for Lack of Utility

I.	THE CLAIMED INVENTION IS THE FOCUS 
OF THE UTILITY REQUIREMENT

The claimed invention is the focus of the assessment of 
whether an applicant has satisfied the utility requirement. 
Each claim (i.e., each "invention"), therefore, must be eval-
uated on its own merits for compliance with all statutory 
requirements. Generally speaking, however, a dependent 
claim will define an invention that has utility if the claim 
from which it depends has defined an invention having util-
ity. An exception to this general rule is where the utility 
specified for the invention defined in a dependent claim 
differs from that indicated for the invention defined in the 
independent claim from which the dependent claim 
depends. Where an applicant has established utility for a 
species that falls within a identified genus of compounds, 
and presents a generic claim covering the genus, as a gen-
eral matter, that claim should be treated as being sufficient 
under 35 U.S.C. 101. Only where it can be established that 
other species clearly encompassed by the claim do not have 
utility should a rejection be imposed on the generic claim. 
In such cases, the applicant should be encouraged to amend 
the generic claim so as to exclude the species that lack util-
ity. A claim that raises this question is likely to be deficient 
under 35 U.S.C. 112, second paragraph, in terms of accu-
rately defining the genus to encompass species that are suf-
ficiently similar to constitute the genus.

It is common and sensible for an applicant to identify 
several specific utilities for an invention, particularly where 
the invention is a product (e.g., a machine, an article of 
manufacture or a composition of matter). However, regard-
less of the category of invention that is claimed (e.g., prod-
uct or process), an applicant need only make one credible 
assertion of specific utility for the claimed invention to sat-
isfy 35 U.S.C. 101 and 35 U.S.C. 112; additional state-
ments of utility, even if not "credible," do not render the 
claimed invention lacking in utility. See, e.g., Raytheon v. 
Roper, 724 F.2d 951, 958, 220 USPQ 592, 598 (Fed. Cir. 
1983), cert. denied, 469 U.S. 835 (1984) ("When a properly 
claimed invention meets at least one stated objective, utility 
under  35 U.S.C. 101 is clearly shown." );  In re Gottlieb, 
328 F.2d 1016, 1019, 140 USPQ 665, 668 (CCPA 1964) 
("Having found that the antibiotic is useful for some pur-
pose, it becomes unnecessary to decide whether it is in fact 
useful for the other purposes `indicated' in the specification 
as possibly useful." ); In re Malachowski, 530 F.2d 1402, 
189 USPQ 432 (CCPA 1976); Hoffman v. Klaus, 9 
USPQ2d 1657 (Bd. Pat. App. & Inter. 1988). Thus, if appli-
cant makes one credible assertion of utility, utility for the 
claimed invention as a whole is established.

Statements made by the applicant in the specification or 
incident to prosecution of the application before the Office 
cannot, standing alone, be the basis for a lack of utility 
rejection under 35 U.S.C. 101 or 35 U.S.C. 112. Tol-O-
Matic, Inc. v. Proma Produkt-Und Mktg. Gesellschaft 
m.b.h., 945 F.2d 1546, 1553, 20 USPQ2d 1332, 1338 (Fed. 
Cir. 1991) (It is not required that a particular characteristic 
set forth in the prosecution history be achieved in order to 
satisfy 35 U.S.C. 101.). An applicant may include state-
ments in the specification whose technical accuracy cannot 
be easily confirmed if those statements are not necessary to 
support the patentability of an invention with regard to any 
statutory basis. Thus, the Office should not require an 
applicant to strike nonessential statements relating to utility 
from a patent disclosure, regardless of the technical accu-
racy of the statement or assertion it presents. Office person-
nel should also be especially careful not to read into a claim 
unclaimed results, limitations or embodiments of an inven-
tion. See Carl Zeiss Stiftung v. Renishaw PLC, 945 F.2d 
1173, 20 USPQ2d 1094 (Fed. Cir. 1991); In re Krimmel, 
292 F.2d 948, 130 USPQ 215 (CCPA 1961). Doing so can 
inappropriately change the relationship of an asserted util-
ity to the claimed invention and raise issues not relevant to 
examination of that claim.

II.	IS THERE AN ASSERTED OR WELL-ESTAB-
LISHED UTILITY FOR THE CLAIMED 
INVENTION?

Upon initial examination, the examiner should review 
the specification to determine if there are any statements 
asserting that the claimed invention is useful for any partic-
ular purpose. A complete disclosure should include a state-
ment which identifies a specific utility for the invention. 

A.	An Asserted Utility Must Be Specific, Not General

A statement of specific utility should fully and clearly 
explain why the applicant believes the invention is useful. 
Such statements will usually explain the purpose of or how 
the invention may be used (e.g., a compound is believed to 
be useful in the treatment of a particular disorder). Regard-
less of the form of statement of specific utility, it must 
enable one ordinarily skilled in the art to understand why 
the applicant believes the claimed invention is useful. 

Except where an invention has a well-established utility, 
the failure of an applicant to specifically identify why an 
invention is believed to be useful renders the claimed 
invention deficient under 35 U.S.C. 101 and 35 U.S.C. 112, 
first paragraph. In such cases, the applicant has failed to 
identify a "specific utility" for the claimed invention. For 
example, a statement that a composition has an unspecified 
"biological activity" or that does not explain why a compo-
sition with that activity is believed to be useful fails to set 
forth a "specific utility." Brenner v. Manson, 383 US 519, 
148 USPQ 689 (1966) (general assertion of similarities to 
known compounds known to be useful without sufficient 
corresponding explanation why claimed compounds are 
believed to be similarly useful insufficient under 35 U.S.C. 
101); In re Ziegler, 992 F.2d 1197, 1201, 26 USPQ2d 1600, 
1604 (Fed. Cir. 1993) (disclosure that composition is "plas-
tic-like" and can form "films" not sufficient to identify spe-
cific utility for invention); In re Kirk, 376 F.2d 936, 153 
USPQ 48 (CCPA 1967) (indication that compound is "bio-
logically active" or has "biological properties" insufficient 
standing alone). See also In re Joly, 376 F.2d 906, 153 
USPQ 45 (CCPA 1967); Kawai v. Metlesics, 480 F.2d 880, 
890, 178 USPQ 158, 165 (CCPA 1973) (contrasting 
description of invention as sedative which did suggest spe-
cific utility to general suggestion of "pharmacological 
effects on the central nervous system" which did not). In 
contrast, a disclosure that identifies a particular biological 
activity of a compound and explains how that activity can 
be utilized in a particular therapeutic application of the 
compound does contain an assertion of specific utility for 
the invention.

Situations where an applicant either fails to indicate why 
an invention is considered useful, or where the applicant 
inaccurately describes the utility should rarely arise. One 
reason for this is that applicants are required to disclose the 
best mode known to them of practicing the invention at the 
time they file their application. An applicant who omits a 
description of the specific utility of the invention, or who 
incompletely describes that utility, may encounter problems 
with respect to the best mode requirement of 35 U.S.C. 112, 
first paragraph.

B.	No Statement of Utility for the Claimed Invention 
in the Specification Does Not Per Se Negate Utility

Occasionally, an applicant will not explicitly state in the 
specification or otherwise assert a specific utility for the 
claimed invention. If no statements can be found asserting a 
specific utility for the claimed invention in the specifica-
tion, Office personnel should determine if the claimed 
invention has a well-established utility. A well-established 
utility is one that would be immediately apparent to a per-
son of ordinary skill based upon disclosed features or char-
acteristics of the invention, or statements made by the 
applicant in the written description of the invention. If an 
invention has a well- established utility, rejections under  
35 U.S.C. 101 and  35 U.S.C. 112, first paragraph, based on 
lack of utility should not be imposed. In re Folkers, 344 
F.2d 970, 145 USPQ 390 (CCPA 1965). For example, if an 
application teaches the cloning and characterization of the 
nucleotide sequence of a well-known protein such as insu-
lin, and those skilled in the art at the time of filing knew 
that insulin had a well-established use, it would be 
improper to reject the claimed invention as lacking utility 
solely because of the omitted statement of specific utility.

If a person of ordinary skill would not immediately rec-
ognize a specific utility for the claimed invention (i.e., why 
it would be useful) based on the characteristics of the 
invention or statements made by the applicant, the Exam-
iner should reject the application under 35 U.S.C. 101 and 
under 35 U.S.C. 112, first paragraph, as failing to identify a 
specific utility for the claimed invention. The rejection 
should clearly indicate that the basis of the rejection is that 
the application fails to identify a specific utility for the 
invention. The rejection should also specify that the appli-
cant must reply by indicating why the invention is believed 
useful and where support for any subsequently asserted 
utility can be found in the specification as filed.

If the applicant subsequently indicates why the invention 
is useful, Office personnel should review that assertion 
according to the standards articulated below for review of 
the credibility of an asserted utility.

III.	EVALUATING THE CREDIBILITY OF AN 
ASSERTED UTILITY

A.	An Asserted Utility Creates a Presumption of 
Utility

In most cases, an applicant's assertion of utility creates a 
presumption of utility that will be sufficient to satisfy the 
utility requirement of  35 U.S.C. 101. See, e.g., In re Jolles, 
628 F.2d 1322, 206 USPQ 885 (CCPA 1980); In re Irons, 
340 F.2d 974, 144 USPQ 351 (CCPA 1965); In re Langer, 
503 F.2d 1380, 183 USPQ 288 (CCPA 1974); In re Sichert, 
566 F.2d 1154, 1159, 196 USPQ 209, 212-13 (CCPA 1977). 
As the Court of Customs and Patent Appeals stated in In re 
Langer:

As a matter of Patent Office practice, a specification which con-
tains a disclosure of utility which corresponds in scope to the 
subject matter sought to be patented must be taken as sufficient to 
satisfy the utility requirement of ? 101 for the entire claimed sub-
ject matter   unless there is a reason for one skilled in the art to 
question the objective truth of the statement of utility or its scope.

In re Langer, 503 F.2d at 1391, 183 USPQ at 297 (empha-
sis in original). The "Langer" test for utility has been used 
by both the Federal Circuit and the Court of Customs and 
Patent Appeals in evaluation of rejections under 35 U.S.C. 
112, first paragraph, where the rejection is based on a defi-
ciency under 35 U.S.C. 101.  In In re Brana, 51 F.3d 1560, 
34 USPQ2d 1436 (Fed. Cir. 1995), the Federal Circuit 
explicitly adopted the Court of Customs and Patent 
Appeals's formulation of the "Langer" standard for 
35 U.S.C. 112, first paragraph rejections, as it was 
expressed in a slightly reworded format in In re Marzocchi, 
439 F.2d 220, 223, 169 USPQ 367, 369 (CCPA 1971), 
namely:

[A] specification disclosure which contains a teaching of the 
manner and process of making and using the invention in terms 
which correspond in scope to those used in describing and defin-
ing the subject matter sought to be patented must be taken as in 
compliance with the enabling requirement of the first paragraph 
of ? 112 unless there is reason to doubt the objective truth of the 
statements contained therein which must be relied on for 
enabling support. (emphasis added).

Thus, Langer and subsequent cases direct the Office to 
presume that a statement of utility made by an applicant is 
true. See In re Langer, 503 F.2d at 1391, 183 USPQ at 297; 
In re Malachowski, 530 F.2d 1402, 1404, 189 USPQ 432, 
435 (CCPA 1976); In re Brana, 51 F.3d 1560, 34 USPQ2d 
1436 (Fed. Cir. 1995). For obvious reasons of efficiency 
and in deference to an applicant's understanding of his or 
her invention, when a statement of utility is evaluated, 
Office personnel should not begin by questioning the truth 
of the statement of utility. Instead, any inquiry must start by 
asking if there is any reason to question the truth of the 
statement of utility. This can be done by simply evaluating 
the logic of the statements made, taking into consideration 
any evidence cited by the applicant. If the asserted utility is 
credible (i.e., believable based on the record or the nature 
of the invention), a rejection based on "lack of utility" is 
not appropriate. Clearly, Office personnel should not begin 
an evaluation of utility by assuming that an asserted utility 
is likely to be false, based on the technical field of the 
invention or for other general reasons.

Compliance with 35 U.S.C. 101 is a question of fact. 
Raytheon v. Roper, 724 F.2d 951, 956, 220 USPQ 592, 596 
(Fed. Cir. 1983) cert. denied, 469 U.S. 835 (1984). Thus, to 
overcome the presumption of truth that an assertion of util-
ity by the applicant enjoys, Office personnel must establish 
that it is more likely than not that one of ordinary skill in 
the art would doubt (i.e., "question") the truth of the state-
ment of utility. The evidentiary standard to be used 
throughout ex parte examination in setting forth a rejection 
is a preponderance of the totality of the evidence under 
consideration.  In re Oetiker, 977 F.2d 1443, 1445, 24 
USPQ2d 1443, 1444 (Fed. Cir. 1992) ("After evidence or 
argument is submitted by the applicant in response, patent-
ability is determined on the totality of the record, by a pre-
ponderance of evidence with due consideration to 
persuasiveness of argument."); In re Corkill, 771 F.2d 
1496, 1500, 226 USPQ 1005, 1008 (Fed. Cir. 1985). A pre-
ponderance of the evidence exists when it suggests that it is 
more likely than not that the assertion in question is true.   
Herman v. Huddleston, 459 U.S. 375, 390 (1983). To do 
this, Office personnel must provide evidence sufficient to 
show that the statement of asserted utility would be consid-
ered "false" by a person of ordinary skill in the art. Of 
course, a person of ordinary skill must have the benefit of 
both facts and reasoning in order to assess the truth of a 
statement. This means that if the applicant has presented 
facts that support the reasoning used in asserting a utility, 
Office personnel must present countervailing facts and rea-
soning sufficient to establish that a person of ordinary skill 
would not believe the applicant's assertion of utility. In re 
Brana, 51 F.3d 1560, 34 USPQ2d 1436 (Fed. Cir. 1995). 
The initial evidentiary standard used during evaluation of 
this question is a preponderance of the evidence (i.e., the 
totality of facts and reasoning suggest that it is more likely 
than not that the statement of the applicant is false). 

B.	When Is an Asserted Utility Not Credible?

Where an applicant has specifically asserted that an 
invention has a particular utility, that assertion cannot sim-
ply be dismissed by Office personnel as being "wrong," 
even when there may be reason to believe that the assertion 
is not entirely accurate. Rather, Office personnel must 
determine if the assertion of utility is credible (i.e., whether 
the assertion of utility is believable to a person of ordinary 
skill in the art based on the totality of evidence and reason-
ing provided). An assertion is credible unless (A) the logic 
underlying the assertion is seriously flawed, or (B) the facts 
upon which the assertion is based are inconsistent with the 
logic underlying the assertion. Credibility as used in this 
context refers to the reliability of the statement based on the 
logic and facts that are offered by the applicant to support 
the assertion of utility.

One situation where an assertion of utility would not be 
considered credible is where a person of ordinary skill 
would consider the assertion to be "incredible in view of 
contemporary knowledge" and where nothing offered by 
the applicant would counter what contemporary knowledge 
might otherwise suggest. Office personnel should be care-
ful, however, not to label certain types of inventions as 
"incredible" or "speculative" as such labels do not provide 
the correct focus for the evaluation of an assertion of utility. 
"  Incredible utility" is a conclusion, not a starting point for 
analysis under 35 U.S.C. 101. A conclusion that an asserted 
utility is incredible can be reached only after the Office has 
evaluated both the assertion of the applicant regarding util-
ity and any evidentiary basis of that assertion. The Office 
should be particularly careful not to start with a presump-
tion that an asserted utility is, per se, "incredible" and the 
proceed to base a rejection under 35 U.S.C. 101 on that pre-
sumption.

Rejections under 35 U.S.C. 101 have been rarely sus-
tained by Federal courts. Generally speaking, in these rare 
cases, the 35 U.S.C. 101 rejection was sustained either 
because the applicant failed to disclose any utility for the 
invention or asserted a utility that could only be true if it 
violated a scientific principle, such as the second law of 
thermodynamics, or a law of nature, or was wholly incon-
sistent with contemporary knowledge in the art. In re 
Gazave, 379 F.2d 973, 978, 154 USPQ 92, 96 (CCPA 
1967). Special care therefore should be taken when assess-
ing the credibility of an asserted therapeutic utility for a 
claimed invention. In such cases, a previous lack of success 
in treating a disease or condition, or the absence of a 
proven animal model for testing the effectiveness of drugs 
for treating a disorder in humans, should not, standing 
alone, serve as a basis for challenging the asserted utility 
under  35 U.S.C. 101.

IV.	INITIAL BURDEN IS ON THE OFFICE TO 
ESTABLISH A PRIMA FACIE CASE AND 
PROVIDE EVIDENTIARY SUPPORT 
THEREOF

To properly reject a claimed invention under  35 U.S.C. 
101, the Office must (A) make a prima facie showing that 
the claimed invention lacks utility, and (B) provide a suffi-
cient evidentiary basis for factual assumptions relied upon 
in establishing the prima facie showing. In re Gaubert, 524 
F.2d 1222, 1224, 187 USPQ 664, 666 (CCPA 1975) 
("Accordingly, the PTO must do more than merely question 
operability - it must set forth factual reasons which would 
lead one skilled in the art to question the objective truth of 
the statement of operability."). If the Office cannot develop 
a proper prima facie case and provide evidentiary support 
for a rejection under 35 U.S.C. 101, a rejection on this 
ground should not be imposed. See, e.g., In re Oetiker, 977 
F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 1992) 
("[T]he examiner bears the initial burden, on review of the 
prior art or on any other ground, of presenting a prima facie 
case of unpatentability. If that burden is met, the burden of 
coming forward with evidence or argument shifts to the 
applicant.... If examination at the initial stage does not pro-
duce a prima facie case of unpatentability, then without 
more the applicant is entitled to grant of the patent."). See 
also Fregeau v. Mossinghoff, 776 F.2d 1034, 227 USPQ 
848 (Fed. Cir. 1985) (applying prima facie case law to  35 
U.S.C. 101); In re Piasecki, 745 F.2d 1468, 223 USPQ 785 
(Fed. Cir. 1984). 

The prima facie showing must be set forth in a well-rea-
soned statement. The statement must articulate sound rea-
sons why a person of ordinary skill in the art would 
conclude that it is more likely than not that an asserted util-
ity is not credible. The statement should specifically iden-
tify the scientific basis of any factual conclusions made in 
the   prima facie showing. The statement must also explain 
why any evidence of record that supports the asserted util-
ity would not be persuasive to one of ordinary skill.

In addition to the statement setting forth the   prima facie 
showing, Office personnel must provide evidentiary sup-
port for the prima facie case. In most cases, documentary 
evidence (e.g., articles in scientific journals, or excerpts 
from patents or scientific treatises) can and should be cited 
to support any factual conclusions made in the   prima facie 
showing. Only when documentary evidence is not readily 
available should the examiner attempt to satisfy the 
Office's requirement for evidentiary support for the factual 
basis of the prima facie showing solely through an explana-
tion of relevant scientific principles. It is imperative that 
Office personnel use specificity in setting forth an initial 
rejection under  35 U.S.C. 101 and support any factual con-
clusions made in the prima facie showing. For example, 
Office personnel should explain why any in vitro or  in vivo 
data supplied by the applicant would not be reasonably pre-
dictive of an asserted therapeutic utility from the perspec-
tive of a person of ordinary skill in the art. By using 
specificity, the applicant will be able to identify the 
assumptions made by the Office in setting forth the rejec-
tion and will be able to address those assumptions properly.

V.	EVIDENTIARY REQUESTS BY AN EXAM-
INER TO SUPPORT AN ASSERTED UTILITY

In appropriate situations the Office may require an appli-
cant to substantiate an asserted utility for a claimed inven-
tion. See In re Pottier, 376 F.2d 328, 330, 153 USPQ 407, 
408 (CCPA 1967) ("When the operativeness of any process 
would be deemed unlikely by one of ordinary skill in the 
art, it is not improper for the examiner to call for evidence 
of operativeness."). See also In re Jolles, 628 F.2d 1322, 
1327, 206 USPQ 885, 890 (CCPA 1980); In re Citron, 325 
F.2d 248, 139 USPQ 516 (CCPA 1963);   In re Novak, 306 
F.2d 924, 928, 134 USPQ 335, 337 (CCPA1962). In In re 
Citron, the court held that when an "alleged utility appears 
to be incredible in the light of the knowledge of the art, or 
factually misleading, applicant must establish the asserted 
utility by acceptable proof."  325 F.2d at 253, 139 USPQ at 
520.  The court approved of the board's decision which 
affirmed the rejection under  35 U.S.C. 101 "in view of the 
art knowledge of the lack of a cure for cancer and the 
absence of any clinical data to substantiate the allegation." 
325 F.2d at 252, 139 USPQ at 519 (emphasis in original). 
The court thus established a higher burden on the applicant 
where the statement of use is incredible or misleading. In 
such a case, the examiner should challenge the use and 
require sufficient evidence of operativeness. The purpose 
for this authority is to enable an applicant to cure an other-
wise defective factual basis for the operability of an inven-
tion. Because this is a curative authority (e.g., evidence is 
requested to enable an applicant to support an assertion that 
is inconsistent with the facts of record in the application), 
Office personnel should indicate not only why the factual 
record is defective in relation to the assertions of the appli-
cant, but also, where appropriate, what type of evidentiary 
showing can be provided by the applicant to remedy the 
problem.

Requests for additional evidence should be imposed 
rarely, and only if necessary to support the scientific credi-
bility of the asserted utility (e.g., if the asserted utility is not 
consistent with the evidence of record and current scientific 
knowledge). As the Federal Circuit recently noted, "[o]nly 
after the PTO provides evidence showing that one of ordi-
nary skill in the art would reasonably doubt the asserted 
utility does the burden shift to the applicant to provide 
rebuttal evidence sufficient to convince such a person of 
the invention's asserted utility." In re Brana, 51 F.3d 1560, 
34 USPQ2d 1436 (Fed. Cir. 1995) (citing In re Bundy, 642 
F.2d 430, 433, 209 USPQ 48, 51 (CCPA 1981)). In 
Brana, the court pointed out that the purpose of 
treating cancer with chemical compounds does not 
suggest, per se, an incredible utility. Where the prior 
art disclosed "structurally similar compounds to those 
claimed by applicants which have been proven in vivo to be 
effective as chemotherapeutic agents against various tumor 
models . . ., one skilled in the art would be without basis to 
reasonably doubt applicants' asserted utility on its face."  
51 F.3d at 1566, 34 USPQ2d at 1441. As courts have stated, 
"it is clearly improper for the examiner to make a demand 
for further test data, which as evidence would be essentially 
redundant and would seem to serve for nothing except per-
haps to unduly burden the applicant." In re Isaacs, 347 F.2d 
887, 890, 146 USPQ 193, 196 (CCPA 1965).

VI.	CONSIDERATION OF A REPLY TO A   PRIMA 
FACIE REJECTION FOR LACK OF UTILITY

If a rejection under  35 U.S.C. 101 has been properly 
imposed, along with a corresponding rejection under  35 
U.S.C. 112, first paragraph, the burden shifts to the appli-
cant to rebut the prima facie showing. In re Oetiker, 977 
F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 1992) 
("The examiner bears the initial burden, on review of the 
prior art or on any other ground, of presenting a prima facie 
case of unpatentability. If that burden is met, the burden of 
coming forward with evidence or argument shifts to the 
applicant. . . After evidence or argument is submitted by the 
applicant in response, patentability is determined on the 
totality of the record, by a preponderance of evidence with 
due consideration to persuasiveness of argument."). An 
applicant can do this using any combination of the follow-
ing: amendments to the claims, arguments or reasoning, or 
new evidence submitted in an affidavit or declaration under  
37 CFR 1.132, or in a printed publication. New evidence 
provided by an applicant must be relevant to the issues 
raised in the rejection. For example, declarations in which 
conclusions are set forth without establishing a nexus 
between those conclusions and the supporting evidence, or 
which merely express opinions, may be of limited proba-
tive value with regard to rebutting a prima facie case. In re 
Grunwell, 609 F.2d 486, 203 USPQ 1055 (CCPA 1979); In 
re Buchner, 929 F.2d 660, 18 USPQ2d 1331 (Fed. Cir. 
1991). See  MPEP ? 716.01(a) through  ? 716.01(c).

Once a reply has been provided, Office personnel must 
review the complete record, including the claims, to deter-
mine if it is appropriate to maintain the rejections under 
35 U.S.C. 101 and 35 U.S.C. 112. If the record as a whole 
would make it more likely than not that the asserted utility 
for the claimed invention would be considered credible by 
a person of ordinary skill in the art, the Office cannot main-
tain the rejection. In re Rinehart, 531 F.2d 1048, 1052, 189 
USPQ 143, 147 (CCPA 1976).

VII.	EVALUATION OF EVIDENCE RELATED TO 
UTILITY

There is no predetermined amount or character of evi-
dence that must be provided by an applicant to support an 
asserted utility, therapeutic or otherwise. Rather, the char-
acter and amount of evidence needed to support an asserted 
utility will vary depending on what is claimed (Ex parte 
Ferguson, 117 USPQ 229 (Bd. App. 1957)), and whether 
the asserted utility appears to contravene established scien-
tific principles and beliefs. In re Gazave, 379 F.2d 973, 978, 
154 USPQ 92, 96 (CCPA 1967); In re Chilowsky, 229 F.2d 
457, 462, 108 USPQ 321, 325 (CCPA 1956). Furthermore, 
the applicant does not have to provide evidence sufficient 
to establish that an asserted utility is true "beyond a reason-
able doubt." In re Irons, 340 F.2d 974, 978, 144 USPQ 351, 
354 (CCPA 1965). Nor must an applicant provide evidence 
such that it establishes an asserted utility as a matter of sta-
tistical certainty. Nelson v. Bowler, 626 F.2d 853, 856-57, 
206 USPQ 881, 883-84 (CCPA 1980) (reversing the Board 
and rejecting Bowler's arguments that the evidence of util-
ity was statistically insignificant. The court pointed out that 
a rigorous correlation is not necessary when the test is rea-
sonably predictive of the response). See also Rey-Bellet v. 
Englehardt, 493 F.2d 1380, 181 USPQ 453 (CCPA 1974) 
(data from animal testing is relevant to asserted human 
therapeutic utility if there is a "satisfactory correlation 
between the effect on the animal and that ultimately 
observed in human beings"). Instead, evidence will be suf-
ficient if, considered as a whole, it leads a person of ordi-
nary skill in the art to conclude that the asserted utility is 
more likely than not true.

2107.02	Special Considerations for Asserted 
Therapeutic or Pharmacological 
Utilities

The Federal courts have consistently reversed rejections 
by the Office asserting a lack of utility for inventions 
claiming a pharmacological or therapeutic utility where an 
applicant has provided evidence that reasonably supports 
such a utility. In view of this, Office personnel should be 
particularly careful in their review of evidence provided in 
support of an asserted therapeutic or pharmacological util-
ity.

I.	A REASONABLE CORRELATION BETWEEN 
THE EVIDENCE AND THE ASSERTED UTIL-
ITY IS SUFFICIENT

As a general matter, evidence of pharmacological or 
other biological activity of a compound will be relevant to 
an asserted therapeutic use if there is a reasonable correla-
tion between the activity in question and the asserted utility. 
Cross v. Iizuka, 753 F.2d 1040, 224 USPQ 739 (Fed. Cir. 
1985); In re Jolles, 628 F.2d 1322, 206 USPQ 885 (CCPA 
1980); Nelson v. Bowler, 626 F.2d 853, 206 USPQ 
881 (CCPA 1980). An applicant can establish this reason-
able correlation by relying on statistically relevant data 
documenting the activity of a compound or composition, 
arguments or reasoning, documentary evidence (e.g., arti-
cles in scientific journals), or any combination thereof. The 
applicant does not have to prove that a correlation exists 
between a particular activity and an asserted therapeutic 
use of a compound as a matter of statistical certainty, nor 
does he or she have to provide actual evidence of success in 
treating humans where such a utility is asserted. Instead, as 
the courts have repeatedly held, all that is required is a rea-
sonable correlation between the activity and the asserted 
use Nelson v. Bowler, 626 F.2d 853, 857, 206 USPQ 881, 
884 (CCPA 1980).

II.	STRUCTURAL SIMILARITY TO COM-
POUNDS WITH ESTABLISHED UTILITY

Courts have routinely found evidence of structural simi-
larity to a compound known to have a particular therapeutic 
or pharmacological utility as being supportive of an asser-
tion of therapeutic utility for a new compound. In In re 
Jolles, 628 F.2d 1322, 206 USPQ 885 (CCPA 1980), the 
claimed compounds were found to have utility based on a 
finding of a close structural relationship to daunorubicin 
and doxorubicin and shared pharmacological activity with 
those compounds, both of which were known to be useful 
in cancer chemotherapy.  The evidence of close structural 
similarity with the known compounds was presented in 
conjunction with evidence demonstrating substantial activ-
ity of the claimed compounds in animals customarily 
employed for screening anticancer agents. Such evidence 
should be given appropriate weight in determining whether 
one skilled in the art would find the asserted utility credi-
ble. Office personnel should evaluate not only the existence 
of the structural relationship, but also the reasoning used by 
the applicant or a declarant to explain why that structural 
similarity is believed to be relevant to the applicant's asser-
tion of utility.

III.	DATA FROM IN VITRO OR ANIMAL TEST-
ING IS GENERALLY SUFFICIENT TO SUP-
PORT THERAPEUTIC UTILITY

If reasonably correlated to the particular therapeutic or 
pharmacological utility, data generated using in vitro 
assays, or from testing in an animal model or a combination 
thereof almost invariably will be sufficient to establish 
therapeutic or pharmacological utility for a compound, 
composition or process. A cursory review of cases involv-
ing therapeutic inventions where 35 U.S.C. 101 was the 
dispositive issue illustrates the fact that the Federal courts 
are not particularly receptive to rejections under 35 U.S.C. 
101 based on inoperability. Most striking is the fact that in 
those cases where an applicant supplied a reasonable evi-
dentiary showing supporting an asserted therapeutic utility, 
almost uniformly the 35 U.S.C. 101-based rejection was 
reversed. See, e.g., In re Brana, 51 F.3d 1560, 34 USPQ 
1436 (Fed. Cir. 1995); Cross v. Iizuka, 753 F.2d 1040, 224 
USPQ 739 (Fed. Cir. 1985); In re Jolles, 628 F.2d 1322, 
206 USPQ 885 (CCPA 1980); Nelson v. Bowler, 626 F.2d 
853, 856, 206 USPQ 881, 883 (CCPA 1980); In re Mala-
chowski, 530 F.2d 1402, 189 USPQ 432 (CCPA 1976); In 
re Gaubert, 530 F.2d 1402, 189 USPQ 432 (CCPA 1975); 
In re Gazave, 379 F.2d 973, 154 USPQ 92 (CCPA 1967); In 
re Hartop, 311 F.2d 249, 135 USPQ 419 (CCPA 1962); In 
re Krimmel, 292 F.2d 948, 130 USPQ 215 (CCPA 1961). 
Only in those cases where the applicant was unable to come 
forward with any relevant evidence to rebut a finding by 
the Office that the claimed invention was inoperative was a  
35 U.S.C. 101 rejection affirmed by the court. In re Citron, 
325 F.2d 248, 253, 139 USPQ 516, 520 (CCPA 1963) (ther-
apeutic utility for an uncharacterized biological extract not 
supported or scientifically credible); In re Buting, 418 F.2d 
540, 543, 163 USPQ 689, 690 (CCPA 1969) (record did not 
establish a credible basis for the assertion that the single 
class of compounds in question would be useful in treating 
disparate types of cancers); In re Novak, 306 F.2d 924, 134 
USPQ 335 (CCPA 1962) (claimed compounds did not have 
capacity to effect physiological activity upon which utility 
claim based). Contrast, however, In re Buting to In re Gard-
ner, 475 F.2d 1389, 177 USPQ 396 (CCPA 1973), reh'g 
denied, 480 F.2d 879 (CCPA 1973), in which the court held 
that utility for a genus was found to be supported through a 
showing of utility for one species. In no case has a Federal 
court required an applicant to support an asserted utility 
with data from human clinical trials.

If an applicant provides data, whether from in vitro 
assays or animal tests or both, to support an asserted utility, 
and an explanation of why that data supports the asserted 
utility, the Office will determine if the data and the explana-
tion would be viewed by one skilled in the art as being rea-
sonably predictive of the asserted utility. See, e.g., Ex parte 
Maas, 9 USPQ2d 1746 (Bd. Pat. App. & Inter. 1987); Ex 
parte Balzarini, 21 USPQ2d 1892 (Bd. Pat. App. & Inter. 
1991). Office personnel must be careful to evaluate all fac-
tors that might influence the conclusions of a person of 
ordinary skill in the art as to this question, including the test 
parameters, choice of animal, relationship of the activity to 
the particular disorder to be treated, characteristics of the 
compound or composition, relative significance of the data 
provided and, most importantly, the explanation offered by 
the applicant as to why the information provided is 
believed to support the asserted utility. If the data supplied 
is consistent with the asserted utility, the Office cannot 
maintain a rejection under  35 U.S.C. 101.

Evidence does not have to be in the form of data from an 
art-recognized animal model for the particular disease or 
disease condition to which the asserted utility relates. Data 
from any test that the applicant reasonably correlates to the 
asserted utility should be evaluated substantively. Thus, an 
applicant may provide data generated using a particular 
animal model with an appropriate explanation as to why 
that data supports the asserted utility. The absence of a cer-
tification that the test in question is an industry-accepted 
model is not dispositive of whether data from an animal 
model is in fact relevant to the asserted utility. Thus, if one 
skilled in the art would accept the animal tests as being rea-
sonably predictive of utility in humans, evidence from 
those tests should be considered sufficient to support the 
credibility of the asserted utility. In re Hartop, 311 F.2d 
249, 135 USPQ 419 (CCPA 1962); In re Krimmel, 292 F.2d 
948, 953, 130 USPQ 215, 219 (CCPA 1961); Ex parte Kre-
pelka, 231 USPQ 746 (Bd. Pat. App. & Inter. 1986). Office 
personnel should be careful not to find evidence unpersua-
sive simply because no animal model for the human disease 
condition had been established prior to the filing of the 
application. See In re Chilowsky, 229 F.2d 457, 461, 108 
USPQ 321, 325 (CCPA 1956) ("The mere fact that some-
thing has not previously been done clearly is not, in itself, a 
sufficient basis for rejecting all applications purporting to 
disclose how to do it."); In re Wooddy, 331 F.2d 636, 639, 
141 USPQ 518, 520 (CCPA 1964) ("It appears that no one 
on earth is certain as of the present whether the process 
claimed will operate in the manner claimed. Yet absolute 
certainty is not required by the law. The mere fact that 
something has not previously been done clearly is not, in 
itself, a sufficient basis for rejecting all applications pur-
porting to disclose how to do it.").

IV.	HUMAN CLINICAL DATA

Office personnel should not impose on applicants the 
unnecessary burden of providing evidence from human 
clinical trials. There is no decisional law that requires an 
applicant to provide data from human clinical trials to 
establish utility for an invention related to treatment of 
human disorders (see In re Isaacs, 347 F.2d 889, 146 USPQ 
193 (CCPA 1963); In re Langer, 503 F.2d 1380, 183 USPQ 
288 (CCPA 1974)), even with respect to situations where 
no art-recognized animal models existed for the human dis-
ease encompassed by the claims. Ex parte Balzarini, 21 
USPQ2d 1892 (Bd. Pat. App. & Inter. 1991) (human clini-
cal data is not required to demonstrate the utility of the 
claimed invention, even though those skilled in the art 
might not accept other evidence to establish the efficacy of 
the claimed therapeutic compositions and the operativeness 
of the claimed methods of treating humans). Before a drug 
can enter human clinical trials, the sponsor, often the appli-
cant, must provide a convincing rationale to those espe-
cially skilled in the art (e.g., the Food and Drug 
Administration) that the investigation may be successful. 
Such a rationale would provide a basis for the sponsor's 
expectation that the investigation may be successful. In 
order to determine a protocol for phase I testing, the first 
phase of clinical investigation, some credible rationale of 
how the drug might be effective or could be effective would 
be necessary. Thus, as a general rule, if an applicant has ini-
tiated human clinical trials for a therapeutic product or pro-
cess, Office personnel should presume that the applicant 
has established that the subject matter of that trial is reason-
ably predictive of having the asserted therapeutic utility. 

V.	SAFETY AND EFFICACY CONSIDERATIONS

The Office must confine its review of patent applications 
to the statutory requirements of the patent law. Other agen-
cies of the government have been assigned the responsibil-
ity of ensuring conformance to standards established by 
statute for the advertisement, use, sale or distribution of 
drugs. The FDA pursues a two-prong test to provide 
approval for testing. Under that test, a sponsor must show 
that the investigation does not pose an unreasonable and 
significant risk of illness or injury and that there is an 
acceptable rationale for the study. As a review matter, there 
must be a rationale for believing that the compound could 
be effective. If the use reviewed by the FDA is not set forth 
in the specification, FDA review may not satisfy  35 U.S.C. 
101. However, if the reviewed use is one set forth in the 
specification, Office personnel must be extremely hesitant 
to challenge utility. In such a situation, experts at the FDA 
have assessed the rationale for the drug or research study 
upon which an asserted utility is based and found it satis-
factory. Thus, in challenging utility, Office personnel must 
be able to carry their burden that there is no sound rationale 
for the asserted utility even though experts designated by 
Congress to decide the issue have come to an opposite con-
clusion. "FDA approval, however, is not a prerequisite for 
finding a compound useful within the meaning of the patent 
laws." In re Brana, 51 F.3d 1560, 34 USPQ2d 1436 (Fed. 
Cir. 1995) (citing Scott v. Finney, 34 F.3d 1058, 1063, 32 
USPQ2d 1115, 1120 (Fed. Cir. 1994)).

Thus, while an applicant may on occasion need to pro-
vide evidence to show that an invention will work as 
claimed, it is improper for Office personnel to request evi-
dence of safety in the treatment of humans, or regarding the 
degree of effectiveness. See In re Sichert, 566 F.2d 1154, 
196 USPQ 209 (CCPA 1977); In re Hartop, 311 F.2d 249, 
135 USPQ 419 (CCPA 1962); In re Anthony, 414 F.2d 
1383, 162 USPQ 594 (CCPA 1969); In re Watson, 517 F.2d 
465, 186 USPQ 11 (CCPA 1975); In re Krimmel, 292 F.2d 
948, 130 USPQ 215 (CCPA 1961); Ex parte Jovanovics, 
211 USPQ 907 (Bd. Pat. App. & Inter. 1981).

VI.	TREATMENT OF SPECIFIC DISEASE CON-
DITIONS

Claims directed to a method of treating or curing a dis-
ease for which there have been no previously successful 
treatments or cures warrant careful review for compliance 
with  35 U.S.C. 101. The credibility of an asserted utility 
for treating a human disorder may be more difficult to 
establish where current scientific understanding suggests 
that such a task would be impossible. Such a determination 
has always required a good understanding of the state of the 
art as of the time that the invention was made. For example, 
prior to the 1980's, there were a number of cases where an 
asserted use in treating cancer in humans was viewed as 
"incredible." In re Jolles, 628 F.2d 1322, 206 USPQ 885 
(CCPA 1980); In re Buting, 418 F.2d 540, 163 USPQ 689 
(CCPA 1969); Ex parte Stevens, 16 USPQ2d 1379 (Bd. Pat. 
App. & Inter. 1990); Ex parte Busse, 1 USPQ2d 1908 (Bd. 
Pat. App. & Inter. 1986); Ex parte Krepelka, 231 USPQ 
746 (Bd. Pat. App. & Inter. 1986); Ex parte Jovanovics, 
211 USPQ 907 (Bd. Pat. App. & Inter. 1981). The fact that 
there is no known cure for a disease, however, cannot serve 
as the basis for a conclusion that such an invention lacks 
utility. Rather, Office personnel must determine if the 
asserted utility for the invention is credible based on the 
information disclosed in the application. Only those claims 
for which an asserted utility is not credible should be 
rejected. In such cases, the Office should carefully review 
what is being claimed by the applicant. An assertion that 
the claimed invention is useful in treating a symptom of an 
incurable disease may be considered credible by a person 
of ordinary skill in the art on the basis of a fairly modest 
amount of evidence or support. In contrast, an assertion that 
the claimed invention will be useful in "curing" the disease 
may require a significantly greater amount of evidentiary 
support to be considered credible by a person of ordinary 
skill in the art. In re Sichert, 566 F.2d 1154, 196 USPQ 209 
(CCPA 1977); In re Jolles, 628 F.2d 1322, 206 USPQ 885 
(CCPA 1980). See also Ex parte Ferguson, 117 USPQ 229 
(Bd. Pat. App. & Inter. 1957).

In these cases, it is important to note that the Food and 
Drug Administration has promulgated regulations that 
enable a party to conduct clinical trials for drugs used to 
treat life threatening and severely-debilitating illnesses, 
even where no alternative therapy exists. See  21 CFR 
312.80-88 (1994). Implicit in these regulations is the recog-
nition that experts qualified to evaluate the effectiveness of 
therapeutics can and often do find a sufficient basis to con-
duct clinical trials of drugs for incurable or previously 
untreatable illnesses. Thus, affidavit evidence from experts 
in the art indicating that there is a reasonable expectation of 
success, supported by sound reasoning, usually should be 
sufficient to establish that such a utility is credible.

2111	Claim Interpretation; Broadest  
Reasonable Interpretation  [R-1]

CLAIMS MUST BE GIVEN THEIR BROADEST 
REASONABLE INTERPRETATION

During patent examination, the pending claims must be 
"given the broadest reasonable interpretation consistent 
with the specification." Applicant always has the opportu-
nity to amend the claims during prosecution and broad 
interpretation by the examiner reduces the possibility that 
the claim, once issued, will be interpreted more broadly 
than is justified. In re Prater, 415 F.2d 1393, 1404-05, 162 
USPQ 541, 550-51 (CCPA 1969) (Claim 9 was directed to 
a process of analyzing data generated by mass spectro-
graphic analysis of a gas. The process comprised selecting 
the data to be analyzed by subjecting the data to a mathe-
matical manipulation. The examiner made rejections under  
35 U.S.C. 101 and 102. In the section 102 rejection, the 
examiner explained that the claim was anticipated by a 
mental process augmented by pencil and paper markings. 
The court agreed that the claim was not limited to using a 
machine to carry out the process since the claim did not 
explicitly set forth the machine. The court explained that 
"reading a claim in light of the specification, to thereby 
interpret limitations explicitly recited in the claim, is a 
quite different thing from `reading limitations of the speci-
fication into a claim,' to thereby narrow the scope of the 
claim by implicitly adding disclosed limitations which have 
no express basis in the claim." The court found that appli-
cant was advocating the latter, e.g., the impermissible 
importation of subject matter from the specification into the 
claim.).  See also In re Morris, 127 F.3d 1048, 1054-55, 44 
USPQ2d 1023, 1027-28 (Fed. Cir. 1997) (The court held 
that the PTO is not required, in the course of prosecution, to 
interpret claims in applications in the same manner as a 
court would in interpreting claims in an infringement suit.  
Rather, the "PTO applies to verbiage of the proposed claims 
the broadest reasonable meaning of the words in their ordi-
nary usage as they would be understood by one of ordinary 
skill in the art, taking into account whatever enlightenment 
by way of definitions or otherwise that may be afforded by 
the written description contained in applicant's specifica-
tion.").   

>The broadest reasonable interpretation of the claims 
must also be consistent with the interpretation that those 
skilled in the art would reach.  In re Cortright, 165 F.3d 
1353, 1359, 49 USPQ2d 1464, 1468 (Fed. Cir. 1999)(The 
Board's construction of the claim limitation "restore hair 
growth" as requiring the hair to be returned to its original 
state was held to be an unreasonably broad interpretation of 
the limitation. The court held that, consistent with appli-
cant's disclosure and the disclosure of three patents from 
analogous arts using the same phrase to require only some 
increase in hair growth, one of ordinary skill would con-
strue "restore hair growth" to mean that the claimed 
method increases the amount of hair grown on the scalp, 
but does not necessarily produce a full head of hair.)<

2111.01	Plain Meaning [R-1]

THE WORDS OF A CLAIM MUST BE GIVEN 
THEIR "PLAIN MEANING" UNLESS THEY ARE 
DEFINED IN THE SPECIFICATION

While the meaning of claims of issued patents are inter-
preted in light of the specification, prosecution history, 
prior art and other claims, this is not the mode of claim 
interpretation to be applied during examination. During 
examination, the claims must be interpreted as broadly as 
their terms reasonably allow. This means that the words of 
the claim must be given their plain meaning unless appli-
cant has provided a clear definition in the specification. In 
re Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. 
Cir. 1989)(discussed below). One must bear in mind that, 
especially in nonchemical cases, the words in a claim are 
generally not limited in their meaning by what is shown or 
disclosed in the specification. It is only when the specifica-
tion provides definitions for terms appearing in the claims 
that the specification can be used in interpreting claim lan-
guage. In re Vogel, 422 F.2d 438, 441, 164 USPQ 619, 622 
(CCPA 1970). There is one exception and that is when an 
element is claimed using language falling under the scope 
of  35 U.S.C. 112, 6th paragraph (often broadly referred to 
as means or step plus function language). In that case, the 
specification must be consulted to determine the structure, 
material, or acts corresponding to the function recited in the 
claim. In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 
(Fed. Cir. 1994)(see  MPEP ? 2181-  ? 2186).

In In re Zletz, supra, the examiner and the Board had 
interpreted claims reading "normally solid polypropylene" 
and "normally solid polypropylene having a crystalline 
polypropylene content" as being limited to "normally solid 
linear high homopolymers of propylene which have a crys-
talline polypropylene content." The court ruled that limita-
tions, not present in the claims, were improperly imported 
from the specification. See also   In re Marosi, 710 F.2d 
799,218 USPQ 289 (Fed. Cir. 1983) ("Claims are not to be 
read in a vacuum, and limitations therein are to be inter-
preted in light of the specification in giving them their 
`broadest reasonable interpretation." 710 F.2d at 802, 218 
USPQ at 292 (quoting In re Okuzawa, 537 F.2d 545, 548, 
190 USPQ 464, 466 (CCPA 1976))(emphasis in original). 
The court looked to the specification to construe "essen-
tially free of alkali metal" as including unavoidable levels 
of impurities but no more.). Compare In re Weiss, 989 F.2d 
1202, 26 USPQ2d 1885 (Fed. Cir. 1993) (unpublished deci-
sion - cannot be cited as precedent) (The claim related to an 
athletic shoe with cleats that "break away at a preselected 
level of force" and thus prevent injury to the wearer. The 
examiner rejected the claims over prior art teaching athletic 
shoes with cleats not intended to break off and rationalized 
that the cleats would break away given a high enough force. 
The court reversed the rejection stating that when interpret-
ing a claim term which is ambiguous, such as `a preselected 
level of force,' we must look to the specification for the 
meaning ascribed to that term by the inventor." The specifi-
cation had defined "preselected level of force..." as that 
level of force at which the breaking away will prevent 
injury to the wearer during athletic exertion. It should be 
noted that the limitation was part of a means plus function 
element.) 

"PLAIN MEANING" REFERS TO THE MEANING 
GIVEN TO THE TERM BY THOSE OF ORDINARY 
SKILL IN THE ART

When not defined by applicant in the specification, the 
words of a claim must be given their plain meaning. In 
other words, they must be read as they would be interpreted 
by those of ordinary skill in the art. In re Sneed, 710 F.2d 
1544, 218 USPQ 385 (Fed. Cir. 1983) (The applicants had 
argued in an amendment after final rejection that the term 
"flexible plastic pipe," as used in the claims, pertained only 
to pipes of 2-inch diameter and 3-inch diameter and not to a 
pipe of 1.5 inch diameter. This definition of "flexible" was 
also advanced in an affidavit. The prior art, however, 
described 1.5 inch pipe as flexible. The court held that the 
specification and the evidence (the prior art) failed to sup-
port the gloss appellants sought to put on the term "flexi-
ble." Note that applicant had not defined "flexible plastic 
pipe" in the specification.); In re Barr, 444 F.2d 588, 597, 
170 USPQ 330, 339 (CCPA 1971) ("The specification in 
this case attempts no definition of the claim language `a 
phenyl radical.' Accordingly we must presume that the 
phrase was used in its commonly accepted technical 
sense.... Applicants] have not referred us to any standard 
work on chemistry which indicates that the commonly 
accepted technical meaning of the words `a phenyl radical', 
without more, would encompass the hydroxyphenyl radi-
cal. On the contrary, Hackh's [Chemical Dictionary] quite 
plainly defines `phenyl' as `the monovalent radical... 
derived from benzene... or phenol.' ").

APPLICANT MAY BE OWN LEXICOGRAPHER

Applicant may be his or her own lexicographer as long 
as the meaning assigned to the term is not repugnant to the 
term's well known usage. In re Hill, 161 F.2d 367, 73 
USPQ 482 (CCPA 1947).  >Any special meaning assigned 
to a term "must be sufficiently clear in the specification that 
any departure from common usage would be so understood 
by a person of experience in the field of the invention." 
Multiform Desiccants Inc. v. Medzam Ltd., 133 F.3d 1473, 
1477, 45 USPQ2d 1429, 1432 (Fed. Cir. 1998).<

2111.02	Weight of Preamble

PREAMBLE IS NONLIMITING UNLESS IT 
BREATHES LIFE AND MEANING INTO THE 
CLAIM

The preamble is not given the effect of a limitation 
unless it breathes life and meaning into the claim. In order 
to limit the claim, the preamble must be "essential to point 
out the invention defined by the claim." Kropa v. Robie, 
187 F.2d 150, 152, 88 USPQ 478, 481 (CCPA 1951) (dis-
cussed below). In claims directed to articles and apparatus, 
any phraseology in the preamble that limits the structure of 
that article or apparatus must be given weight. In re Stencel, 
828 F.2d 751, 4 USPQ2d 1071 (Fed. Cir. 1987) (discussed 
below). On the other hand, a preamble is generally not 
accorded any patentable weight where it merely recites the 
purpose of a process or the intended use of a structure, and 
where the body of the claim does not depend on the pream-
ble for completeness but, instead, the process steps or struc-
tural limitations are able to stand alone.   In re Hirao, 535 
F.2d 67, 190 USPQ 15 (CCPA 1976) (process claims, dis-
cussed below); Kropa v. Robie, 187 F.2d at 152, 88 USPQ 
at 481 (claims directed to apparatus, products, chemical 
structure, etc., as discussed below).

In   In re Hirao, 535 F.2d 67, 190 USPQ 15 (CCPA 
1976), the claim preamble set forth "A process for prepar-
ing foods and drinks sweetened mildly, and protected 
against discoloration, Streckler's reaction, and moisture 
absorption." The body of the claim recited two steps 
directed to the formation of high purity maltose and a third 
step of adding the maltose to foods and drinks as a sweet-
ener. The court held that the preamble was only directed to 
the purpose of the process, the steps could stand alone and 
did not depend on the preamble for completeness.

In   Kropa v. Robie, 187 F.2d 150, 152, 88 USPQ 478, 
481 (CCPA 1951), a preamble reciting "An abrasive arti-
cle" was deemed essential to point out the invention 
defined by claims to an article comprising abrasive grains 
and a hardened binder and the process of making it. The 
court said that "it is only by that phrase that it can be known 
that the subject matter defined by the claims is comprised 
as an abrasive article. Every union of substances capable 
inter alia of use as abrasive grains and a binder is not an 
`abrasive article.' " Id. at 481, 187 F.2d at 152. Therefore, 
the preamble served to further define the structure of the 
article produced.

In In re Stencel, 828 F.2d 751, 4 USPQ2d 1071 (Fed. Cir. 
1987), the claim was directed to a driver for setting a joint 
of a threaded collar. The claim did not directly include the 
structure of the collar as part of the claimed article. The 
preamble did set forth the structure of the collar but the 
examiner had not given this recitation any weight. The 
court found that the collar structure could not be ignored. 
While the claim was not directly limited to the collar, the 
collar structure recited in the preamble did limit the struc-
ture of the driver. The court stated that "the framework - the 
teachings of the prior art - against which patentability is 
measured is not all drivers broadly, but drivers suitable for 
use in combination with this collar, for the claims are so 
limited." Id. at 1073, 828 F.2d at 754. 

COMPOSITION CLAIMS - THE PREAMBLE IS 
GENERALLY NONLIMITING IF THE PREAMBLE 
MERELY RECITES AN INHERENT PROPERTY

When the claim is directed to a product, the preamble is 
generally nonlimiting if the body of the claim is directed to 
an old composition and the preamble merely recites a prop-
erty inherent in the old composition. Kropa v. Robie, 187 
F.2d at 152, 88 USPQ at 480-81.

THE INTENDED USE MAY FURTHER LIMIT THE 
CLAIM IF IT DOES MORE THAN MERELY STATE 
PURPOSE OR INTENDED USE 

Intended use recitations and other types of functional 
language cannot be entirely disregarded. However, in appa-
ratus, article, and composition claims, intended use must 
result in a structural difference between the claimed inven-
tion and the prior art in order to patentably distinguish the 
claimed invention from the prior art. If the prior art struc-
ture is capable of performing the intended use, then it meets 
the claim. In a claim drawn to a process of making, the 
intended use must result in a manipulative difference as 
compared to the prior art. In re Casey, 370 F.2d 576, 152 
USPQ 235 (CCPA 1967);   In re Otto, 312 F.2d 937, 938, 
136 USPQ 458, 459 (CCPA 1963) (The claims were 
directed to a core member for hair curlers and a process of 
making a core member for hair curlers. Court held that the 
intended use of hair curling was of no significance to the 
structure and process of making.)

2111.03	Transitional Phrases [R-1]

The transitional phrases "comprising", "consisting 
essentially of" and "consisting of" define the scope of a 
claim with respect to what unrecited additional components 
or steps, if any, are excluded from the scope of the claim.

The transitional term "comprising", which is synony-
mous with "including," "containing," or "characterized 
by," is inclusive or open-ended and does not exclude addi-
tional, unrecited elements or method steps. Moleculon 
Research Corp. v. CBS, Inc., 793 F.2d 1261, 229 USPQ 805 
(Fed. Cir. 1986); In re Baxter, 656 F.2d 679, 686, 210 
USPQ 795, 803 (CCPA 1981); Ex parte Davis, 80 USPQ 
448, 450 (Bd. App. 1948)("comprising" leaves "the claim 
open for the inclusion of unspecified ingredients even in 
major amounts").

The transitional phrase "consisting of" excludes any ele-
ment, step, or ingredient not specified in the claim. In re 
Gray, 53 F.2d 520, 11 USPQ 255 (CCPA 1931); Ex parte 
Davis, 80 USPQ 448, 450 (Bd. App. 1948)("consisting of" 
defined as "closing the claim to the inclusion of materials 
other than those recited except for impurities ordinarily 
associated therewith."). Transitional phrases such as "com-
posed of," "having," or "being" must be interpreted in light 
of the specification to determine whether open or closed 
claim language is intended.  >See, e.g., Regents of the Univ. 
of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1573, 43 USPQ2d 
1398, 1410 (Fed. Cir. 1997), cert. denied, 118 S. Ct. 1548 
(1998)(In the context of a cDNA having a sequence coding 
for human PI, the term "having" still permitted inclusion of 
other moieties.).<  A claim which depends from a claim 
which "consists of" the recited elements or steps cannot 
add an element or step.  When the phrase "consists of" 
appears in a clause of the body of a claim, rather than 
immediately following the preamble, it limits only the ele-
ment set forth in that clause; other elements are not 
excluded from the claim as a whole. Mannesmann Demag 
Corp. v. Engineered Metal Products Co., 793 F.2d 1279, 
230 USPQ 45 (Fed. Cir. 1986).

The transitional phrase "consisting essentially of" limits 
the scope of a claim to the specified materials or steps "and 
those that do not materially affect the basic and novel char-
acteristic(s)" of the claimed invention. In re Herz, 537 F.2d 
549, 551-52, 190 USPQ 461, 463 (CCPA 1976) (emphasis 
in original)(Prior art hydraulic fluid required a dispersant 
which appellants argued was excluded from claims limited 
to a functional fluid "consisting essentially of" certain com-
ponents. In finding the claims did not exclude the prior art 
dispersant, the court noted that appellants' specification 
indicated the claimed composition can contain any well-
known additive such as a dispersant, and there was no evi-
dence that the presence of a dispersant would materially 
affect the basic and novel characteristic of the claimed 
invention.  The prior art composition had the same basic 
and novel characteristic (increased oxidation resistance) as 
well as additional enhanced detergent and dispersant char-
acteristics.).  >"A `consisting essentially of' claim occupies 
a middle ground between closed claims that are written in a 
`consisting of'  format and fully open claims that are 
drafted in a `comprising' format." PPG Industries v. 
Guardian Industries, 156 F.3d 1351, 1354, 48 USPQ2d 
1351, 1353-54 (Fed. Cir. 1998).<  See also Atlas Powder 
Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 224 
USPQ 409 (Fed. Cir. 1984); In re Janakirama-Rao, 317 
F.2d 951, 137 USPQ 893 (CCPA 1963); Water Technolo-
gies Corp. v. Calco, Ltd., 850 F.2d 660, 7 USPQ2d 1097 
(Fed. Cir. 1988).  >For search and examination purposes, 
absent a clear indication in the specification of what the 
basic and novel characteristics actually are, "consisting 
essentially of" will be construed as equivalent to "compris-
ing." See, e.g., PPG, 156 F.3d at 1355, 48 USPQ at 1355 
("PPG could have defined the scope of the phrase `consist-
ing essentially of' for purposes of its patent by making 
clear in its specification what it regarded as constituting a 
material change in the basic and novel characteristics of the 
invention.").<  When an applicant contends that additional 
steps or materials in the prior art are excluded by the recita-
tion of "consisting essentially of," applicant has the burden 
of showing that the introduction of additional steps or com-
ponents would materially change the characteristics of 
applicant's invention. In re De Lajarte, 337 F.2d 870, 143 
USPQ 256 (CCPA 1964).  See also Ex parte Hoffman, 12 
USPQ2d 1061, 1063-64 (Bd. Pat. App. & Inter. 
1989)("Although `consisting essentially of' is typically 
used and defined in the context of compositions of matter, 
we find nothing intrinsically wrong with the use of such 
language as a modifier of method steps. . . [rendering] the 
claim open only for the inclusion of steps which do not 
materially affect the basic and novel characteristics of the 
claimed method.  To determine the steps included versus 
excluded the claim must be read in light of the specifica-
tion. . . .  [I]t is an applicant's burden to establish that a step 
practiced in a prior art method is excluded from his claims 
by `consisting essentially of' language."). 

2112	Requirements of Rejection Based on 
Inherency; Burden of Proof [R-1]

The express, implicit, and inherent disclosures of a prior 
art reference may be relied upon in the rejection of claims 
under  35 U.S.C. 102 or 103.  "The inherent teaching of a 
prior art reference, a question of fact, arises both in the con-
text of anticipation and obviousness." In re Napier, 55 F.3d 
610, 613, 34 USPQ2d 1782, 1784 (Fed. Cir. 1995)(affirmed 
a  35 U.S.C. 103 rejection based in part on inherent disclo-
sure in one of the references).  See also In re Grasselli, 713 
F.2d 731, 739, 218 USPQ 769, 775 (Fed. Cir. 1983).

SOMETHING WHICH IS OLD DOES NOT BECOME 
PATENTABLE UPON THE DISCOVERY OF A NEW 
PROPERTY

The claiming of a new use, new function or unknown 
property which is inherently present in the prior art does 
not necessarily make the claim patentable. In re Best, 562 
F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977).  
See also  MPEP ? 2112.01 with regard to inherency and 
product-by-process claims and  MPEP ? 2141.02 with 
regard to inherency and rejections under  35 U.S.C. 103.

A REJECTION UNDER 35 U.S.C. 102/103 CAN BE 
MADE WHEN THE PRIOR ART PRODUCT SEEMS 
TO BE IDENTICAL EXCEPT THAT THE PRIOR 
ART IS SILENT AS TO AN INHERENT CHARAC-
TERISTIC

Where applicant claims a composition in terms of a 
function, property or characteristic and the composition of 
the prior art is the same as that of the claim but the function 
is not explicitly disclosed by the reference, the examiner 
may make a rejection under both 35 U.S.C. 102 and 103, 
expressed as a 102/103 rejection. "There is nothing incon-
sistent in concurrent rejections for obviousness under 
35 U.S.C. 103 and for anticipation under 35 U.S.C. 102." 
In re Best, 562 F.2d 1252, 1255 n.4, 195 USPQ 430, 433 
n.4 (CCPA 1977). This same rationale should also apply to 
product, apparatus, and process claims claimed in terms of 
function, property or characteristic. Therefore, 35 U.S.C. 
102/103 rejection is appropriate for these types of claims as 
well as for composition claims. 

EXAMINER MUST PROVIDE RATIONALE OR EVI-
DENCE TENDING TO SHOW INHERENCY

The fact that a certain result or characteristic may occur 
or be present in the prior art is not sufficient to establish the 
inherency of that result or characteristic. In re Rijckaert, 9 
F.3d 1531, 1534, 28 USPQ2d 1955, 1957 (Fed. Cir. 
1993)(reversed rejection because inherency was based on 
what would result due to optimization of conditions, not 
what was necessarily present in the prior art); In re Oelrich, 
666 F.2d 578, 581-82, 212 USPQ 323, 326 (CCPA 1981).  
>"To establish inherency, the extrinsic evidence `must 
make clear that the missing descriptive matter is necessar-
ily present in the thing described in the reference, and that 
it would be so recognized by persons of ordinary skill. 
Inherency, however, may not be established by probabili-
ties or possibilities. The mere fact that a certain thing may 
result from a given set of circumstances is not sufficient.' " 
In re Robertson, 169 F.3d 743, 745, 49 USPQ2d 1949, 
1950-51 (Fed. Cir. 1999)(citations omitted)(The claims 
were drawn to a disposable diaper having three fastening 
elements. The reference disclosed two fastening elements 
that could perform the same function as the three fastening 
elements in the claims. The court construed the claims to 
require three separate elements and held that the reference 
did not disclose a separate third fastening element, either 
expressly or inherently.).< 

"In relying upon the theory of inherency, the examiner 
must provide a basis in fact and/or technical reasoning to 
reasonably support the determination that the allegedly 
inherent characteristic necessarily flows from the teachings 
of the applied prior art." Ex parte Levy, 17 USPQ2d 1461, 
1464 (Bd. Pat. App. & Inter. 1990) (emphasis in original) 
(Applicant's invention was directed to a biaxially oriented, 
flexible dilation catheter balloon (a tube which expands 
upon inflation) used, for example, in clearing the blood 
vessels of heart patients). The examiner applied a U.S. 
patent to Schjeldahl which disclosed injection molding a 
tubular preform and then injecting air into the preform to 
expand it against a mold (blow molding). The reference did 
not directly state that the end product balloon was biaxially 
oriented. It did disclose that the balloon was "formed from 
a thin flexible inelastic, high tensile strength, biaxially ori-
ented synthetic plastic material." Id. at 1462 (emphasis in 
original). The examiner argued that Schjeldahl's balloon 
was inherently biaxially oriented. The Board reversed on 
the basis that the examiner did not provide objective evi-
dence or cogent technical reasoning to support the conclu-
sion of inherency.).

In In re Schreiber, 128 F.3d 1473, 44 USPQ2d 1429 
(Fed. Cir. 1997), the court affirmed a finding that a prior 
patent to a conical spout used primarily to dispense oil from 
an oil can inherently performed the functions recited in 
applicant's claim to a conical container top for dispensing 
popped popcorn.  The examiner had asserted inherency 
based on the structural similarity between the patented 
spout and applicant's disclosed top, i.e., both structures had 
the same general shape. The court stated:

[N]othing in Schreiber's [applicant's] claim suggests that 
Schreiber's container is of a `different shape' than Harz's 
[patent].  In fact, [ ] an embodiment according to Harz (Fig. 5) 
and the embodiment depicted in Fig. 1 of Schreiber's application 
have the same general shape.  For that reason, the examiner was 
justified in concluding that the opening of a conically shaped top 
as disclosed by Harz is inherently of a size sufficient to `allow [ ] 
several kernels of popped popcorn to pass through at the same 
time' and that the taper of Harz's conically shaped top is inher-
ently of such a shape `as to by itself jam up the popped popcorn 
before the end of the cone and permit the dispensing of only a 
few kernels at a shake of a package when the top is mounted to 
the container.' The examiner therefore correctly found that Harz 
established a prima facie case of anticipation.

In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1432.

ONCE A REFERENCE TEACHING PRODUCT 
APPEARING TO BE SUBSTANTIALLY IDENTI-
CAL IS MADE THE BASIS OF A REJECTION AND 
THE EXAMINER PRESENTS EVIDENCE OR REA-
SONING TENDING TO SHOW INHERENCY, THE 
BURDEN SHIFTS TO THE APPLICANT TO SHOW 
AN UNOBVIOUS DIFFERENCE

"[T]he PTO can require an applicant to prove that the 
prior art products do not necessarily or inherently possess 
the characteristics of his [or her] claimed product. Whether 
the rejection is based on `inherency' under 35 U.S.C. 102, 
on `prima facie obviousness' under 35 U.S.C. 103, jointly 
or alternatively, the burden of proof is the same...[footnote 
omitted]." The burden of proof is similar to that required 
with respect to product-by-process claims. In re Fitzgerald, 
619 F. 2d 67, 70,   205 USPQ 594, 596 (CCPA 1980) (quot-
ing In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433-34 
(CCPA 1977)).

In In re Fitzgerald, the claims were directed to a self-
locking screw-threaded fastener comprising a metallic 
threaded fastener having patches of crystallizable thermo-
plastic bonded thereto. The claim further specified that the 
thermoplastic had a reduced degree of crystallization 
shrinkage. The specification disclosed that the locking fas-
tener was made by heating the metal fastener to melt a ther-
moplastic blank which is pressed against the metal. After 
the thermoplastic adheres to the metal fastener, the end 
product is cooled by quenching in water. The examiner 
made a rejection based on a U.S. patent to Barnes. Barnes 
taught a self-locking fastener in which the patch of thermo-
plastic was made by depositing thermoplastic powder on a 
metallic fastener which was then heated. The end product 
was cooled in ambient air, by cooling air or by contacting 
the fastener with a water trough. The court first noted that 
the two fasteners were identical or only slightly different 
from each other. "Both fasteners possess the same utility, 
employ the same crystallizable polymer (nylon 11), and 
have an adherent plastic patch formed by melting and then 
cooling the polymer." Id. at 596 n.1, 619 F.2d at 70 n,l. The 
court then noted that the Board had found that Barnes' 
cooling rate could reasonably be expected to result in a 
polymer possessing the claimed crystallization shrinkage 
rate. Applicant had not rebutted this finding with evidence 
that the shrinkage rate was indeed different. They had only 
argued that the crystallization shrinkage rate was dependent 
on the cool down rate and that the cool down rate of Barnes 
was much slower than theirs. Because a difference in the 
cool down rate does not necessarily result in a difference in 
shrinkage, objective evidence was required to rebut the  
35 U.S.C. 102/103 prima facie case.

In In re Schreiber, 128 F.3d 1473, 1478, 44 USPQ2d 
1429, 1432 (Fed.Cir.1997), the court held that applicant's 
declaration failed to overcome a prima facie case of antici-
pation because the declaration did not specify the dimen-
sions of either the dispensing top that was tested or the 
popcorn that was used.  Applicant's declaration merely 
asserted that a conical dispensing top built according to a 
figure in the prior art patent was too small to jam and dis-
pense popcorn and thus could not inherently perform the 
functions recited in applicant's claims. The court pointed 
out the disclosure of the prior art patent was not limited to 
use as an oil can dispenser, but rather was broader than the 
precise configuration shown in the patent's figure.  The 
court also noted that the Board of Patent Appeals and Inter-
ferences found as a factual matter that a scaled-up version 
of the top disclosed in the patent would be capable of per-
forming the functions recited in applicant's claim.

See  MPEP ? 2113 for more information on the analo-
gous burden of proof applied to product-by-process claims.

2112.01	Composition, Product, and  
Apparatus Claims

PRODUCT AND APPARATUS CLAIMS - WHEN 
THE STRUCTURE RECITED IN THE REFERENCE 
IS SUBSTANTIALLY IDENTICAL TO THAT OF 
THE CLAIMS, CLAIMED PROPERTIES OR 
FUNCTIONS ARE PRESUMED TO BE INHERENT

Where the claimed and prior art products are identical or 
substantially identical in structure or composition, or are 
produced by identical or substantially identical processes, a 
prima facie case of either anticipation or obviousness has 
been established. In re Best, 562 F.2d 1252, 1255, 195 
USPQ 430, 433 (CCPA 1977). "When the PTO shows a 
sound basis for believing that the products of the applicant 
and the prior art are the same, the applicant has the burden 
of showing that they are not." In re Spada, 911 F.2d 705, 
709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). Therefore, 
the   prima facie case can be rebutted by evidence showing 
that the prior art products do not necessarily possess the 
characteristics of the claimed product. In re Best, 562 F.2d 
at 1255, 195 USPQ at 433.  See also Titanium Metals Corp. 
v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985) 
(Claims were directed to a titanium alloy containing 0.2-
0.4% Mo and 0.6-0.9% Ni having corrosion resistance. A 
Russian article disclosed a titanium alloy containing 0.25% 
Mo and 0.75% Ni but was silent as to corrosion resistance. 
The Federal Circuit held that the claim was anticipated 
because the percentages of Mo and Ni were squarely within 
the claimed ranges. The court went on to say that it was 
immaterial what properties the alloys had or who discov-
ered the properties because the composition is the same and 
thus must necessarily exhibit the properties.).

See also   In re Ludtke, 441 F.2d 660, 169 USPQ 563 
(CCPA 1971) (Claim 1 was directed to a parachute canopy 
having concentric circumferential panels radially separated 
from each other by radially extending tie lines. The panels 
were separated "such that the critical velocity of each suc-
cessively larger panel will be less than the critical velocity 
of the previous panel, whereby said parachute will sequen-
tially open and thus gradually decelerate." The court found 
that the claim was anticipated by Menget. Menget taught a 
parachute having three circumferential panels separated by 
tie lines. The court upheld the rejection finding that appli-
cant had failed to show that   Menget   did not possess the 
functional characteristics of the claims.); Northam Warren 
Corp. v. D. F. Newfield Co., 7 F. Supp. 773, 22 USPQ 313 
(E.D.N.Y. 1934) (A patent to a pencil for cleaning finger-
nails was held invalid because a pencil of the same struc-
ture for writing was found in the prior art.).

COMPOSITION CLAIMS - IF THE COMPOSITION 
IS PHYSICALLY THE SAME, IT MUST HAVE THE 
SAME PROPERTIES

"Products of identical chemical composition can not 
have mutually exclusive properties." A chemical composi-
tion and its properties are inseparable. Therefore, if the 
prior art teaches the identical chemical structure, the prop-
erties applicant discloses and/or claims are necessarily 
present.   In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 
1658 (Fed. Cir. 1990) (Applicant argued that the claimed 
composition was a pressure sensitive adhesive containing a 
tacky polymer while the product of the reference was hard 
and abrasion resistant. "The Board correctly found that the 
virtual identity of monomers and procedures sufficed to 
support a prima facie case of unpatentability of Spada's 
polymer latexes for lack of novelty.").

2112.02	Process Claims

PROCESS CLAIMS - PRIOR ART DEVICE ANTICI-
PATES A CLAIMED PROCESS IF THE DEVICE 
CARRIES OUT THE PROCESS DURING NORMAL 
OPERATION

Under the principles of inherency, if a prior art device, in 
its normal and usual operation, would necessarily perform 
the method claimed, then the method claimed will be con-
sidered to be anticipated by the prior art device. When the 
prior art device is the same as a device described in the 
specification for carrying out the claimed method, it can be 
assumed the device will inherently perform the claimed 
process. In re King, 801 F.2d 1324, 231 USPQ 136 (Fed. 
Cir. 1986) (The claims were directed to a method of 
enhancing color effects produced by ambient light through 
a process of absorption and reflection of the light off a 
coated substrate. A prior art reference to Donley disclosed a 
glass substrate coated with silver and metal oxide 200-800 
angstroms thick. While Donley disclosed using the coated 
substrate to produce architectural colors, the absorption and 
reflection mechanisms of the claimed process were not dis-
closed. However, King's specification disclosed using a 
coated substrate of Donley's structure for use in his pro-
cess. The Federal Circuit upheld the Board's finding that 
"Donley inherently performs the function disclosed in the 
method claims on appeal when that device is used in `nor-
mal and usual operation' " and found that a prima facie 
case of anticipation was made out. Id. at 138, 801 F.2d at 
1326. It was up to applicant to prove that Donley's structure 
would not perform the claimed method when placed in 
ambient light.).  See also In re Best, 562 F.2d 1252, 1255, 
195 USPQ 430, 433 (CCPA 1977) (Applicant claimed a 
process for preparing a hydrolytically-stable zeolitic alumi-
nosilicate which included a step of "cooling the steam zeo-
lite ... at a rate sufficiently rapid that the cooled zeolite 
exhibits a X-ray diffraction pattern ...." All the process lim-
itations were expressly disclosed by a U.S. patent to Hans-
ford except the cooling step. The court stated that any 
sample of Hansford's zeolite would necessarily be cooled 
to facilitate subsequent handling. Therefore, a prima facie 
case under 35 U.S.C. 102/103 was made. Applicant had 
failed to introduce any evidence comparing X-ray diffrac-
tion patterns showing a difference in cooling rate between 
the claimed process and that of Hansford or any data show-
ing that the process of Hansford would result in a product 
with a different X-ray diffraction. Either type of evidence 
would have rebutted the prima facie case under  35 U.S.C. 
102. A further analysis would be necessary to determine if 
the process was unobvious under  35 U.S.C. 103.); Ex parte 
Novitski, 26 USPQ2d 1389 (Bd. Pat. App. & Inter. 1993) 
(The Board rejected a claim directed to a method for pro-
tecting a plant from plant pathogenic nematodes by inocu-
lating the plant with a nematode inhibiting strain of P. 
cepacia. A U.S. patent to Dart disclosed inoculation using 
P. cepacia type Wisconsin 526 bacteria for protecting the 
plant from fungal disease. Dart was silent as to nematode 
inhibition but the Board concluded that nematode inhibi-
tion was an inherent property of the bacteria. The Board 
noted that applicant had stated in the specification that Wis-
consin 526 possesses an 18% nematode inhibition rating.). 

PROCESS OF USE CLAIMS - NEW AND UNOBVI-
OUS USES OF OLD STRUCTURES AND COMPOSI-
TIONS MAY BE PATENTABLE

The discovery of a new use for an old structure based on 
unknown properties of the structure might be patentable to 
the discoverer as a process of using. In re Hack, 245 F.2d 
246, 248, 114 USPQ 161, 163 (CCPA 1957). However, 
when the claim recites using an old composition or struc-
ture and the "use" is directed to a result or property of that 
composition or structure, then the claim is anticipated. In re 
May, 574 F.2d 1082, 1090, 197 USPQ 601, 607 (CCPA 
1978) (Claims 1 and 6, directed to a method of effecting 
nonaddictive analgesia (pain reduction) in animals, were 
found to be anticipated by the applied prior art which dis-
closed the same compounds for effecting analgesia but 
which was silent as to addiction. The court upheld the 
rejection and stated that the applicants had merely found a 
new property of the compound and such a discovery did not 
constitute a new use. The court went on to reverse the 
rejection of claims 2-5 and 7-10 which recited a process of 
using a new compound. The court relied on evidence show-
ing that the nonaddictive property of the new compound 
was unexpected.). 

See also   In re Tomlinson, 363 F.2d 928, 150 USPQ 623 
(CCPA 1966) (The claim was directed to a process of inhib-
iting light degradation of polypropylene by mixing it with 
one of a genus of compounds, including nickel dithiocar-
bamate. A reference taught mixing polypropylene with 
nickel dithiocarbamate to lower heat degradation. The court 
held that the claims read on the obvious process of mixing 
polypropylene with the nickel dithiocarbamate and that the 
preamble of the claim was merely directed to the result of 
mixing the two materials. "While the references do not 
show a specific recognition of that result, its discovery by 
appellants is tantamount only to finding a property in the 
old composition." 363 F.2d at 934, 150 USPQ at 628 
(emphasis in original).). 

2113	Product-by-Process Claims

PRODUCT-BY-PROCESS CLAIMS ARE NOT LIM-
ITED TO THE MANIPULATIONS OF THE 
RECITED STEPS, ONLY THE STRUCTURE 
IMPLIED BY THE STEPS

"[E]ven though product-by-process claims are limited by 
and defined by the process, determination of patentability is 
based on the product itself. The patentability of a product 
does not depend on its method of production. If the product 
in the product-by-process claim is the same as or obvious 
from a product of the prior art, the claim is unpatentable 
even though the prior product was made by a different pro-
cess."   In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 
966 (Fed. Cir. 1985) (citations omitted) (Claim was 
directed to a novolac color developer. The process of mak-
ing the developer was allowed. The difference between the 
inventive process and the prior art was the addition of metal 
oxide and carboxylic acid as separate ingredients instead of 
adding the more expensive pre-reacted metal carboxylate. 
The product-by-process claim was rejected because the end 
product, in both the prior art and the allowed process, ends 
up containing metal carboxylate. The fact that the metal 
carboxylate is not directly added, but is instead produced 
in-situ does not change the end product.).

ONCE A PRODUCT APPEARING TO BE SUBSTAN-
TIALLY IDENTICAL IS FOUND AND A 35 U.S.C. 
102/103 REJECTION MADE, THE BURDEN SHIFTS 
TO THE APPLICANT TO SHOW AN UNOBVIOUS 
DIFFERENCE

"The Patent Office bears a lesser burden of proof in 
making out a case of prima facie obviousness for product-
by-process claims because of their peculiar nature" than 
when a product is claimed in the conventional fashion. In re 
Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 
1974). Once the Examiner provides a rationale tending to 
show that the claimed product appears to be the same or 
similar to that of the prior art, although produced by a dif-
ferent process, the burden shifts to applicant to come for-
ward with evidence establishing an unobvious difference 
between the claimed product and the prior art product. In re 
Marosi, 710 F.2d 798, 802, 218 USPQ 289, 292 (Fed. Cir. 
1983) (The claims were directed to a zeolite manufactured 
by mixing together various inorganic materials in solution 
and heating the resultant gel to form a crystalline metal sili-
cate essentially free of alkali metal. The prior art described 
a process of making a zeolite which, after ion exchange to 
remove alkali metal, appeared to be "essentially free of 
alkali metal." The court upheld the rejection because the 
applicant had not come forward with any evidence that the 
prior art was not "essentially free of alkali metal" and 
therefore a different and unobvious product.). 

Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. & Inter. 
1989) (The prior art disclosed human nerve growth factor 
(b-NGF) isolated from human placental tissue. The claim 
was directed to b-NGF produced through genetic engineer-
ing techniques. The factor produced seemed to be substan-
tially the same whether isolated from tissue or produced 
through genetic engineering. While the applicant ques-
tioned the purity of the prior art factor, no concrete evi-
dence of an unobvious difference was presented. The Board 
stated that the dispositive issue is whether the claimed fac-
tor exhibits any unexpected properties compared with the 
factor disclosed by the prior art. The Board further stated 
that the applicant should have made some comparison 
between the two factors to establish unexpected properties 
since the materials appeared to be identical or only slightly 
different.).

THE USE OF 35 U.S.C. 102/103 REJECTIONS FOR 
PRODUCT-BY-PROCESS CLAIMS HAS BEEN 
APPROVED BY THE COURTS

"[T]he lack of physical description in a product-by-pro-
cess claim makes determination of the patentability of the 
claim more difficult, since in spite of the fact that the claim 
may recite only process limitations, it is the patentability of 
the product claimed and not of the recited process steps 
which must be established. We are therefore of the opinion 
that when the prior art discloses a product which reason-
ably appears to be either identical with or only slightly dif-
ferent than a product claimed in a product-by-process 
claim, a rejection based alternatively on either section 102 
or section 103 of the statute is eminently fair and accept-
able. As a practical matter, the Patent Office is not 
equipped to manufacture products by the myriad of pro-
cesses put before it and then obtain prior art products and 
make physical comparisons therewith." In re Brown, 459 
F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972).

2114	Apparatus and Article Claims - 
Functional Language [R-1]

For a discussion of case law which provides guidance in 
interpreting the functional portion of means-plus-function 
limitations see  MPEP ? 2181 -  ? 2186.

APPARATUS CLAIMS MUST BE STRUCTURALLY 
DISTINGUISHABLE FROM THE PRIOR ART

Claims directed to apparatus must be distinguished from 
the prior art in terms of structure rather than function. In re 
Danly, 263 F.2d 844, 847, 120 USPQ 528, 531 (CCPA 
1959). "[A]pparatus claims cover what a device   is, not 
what a device   does."(emphasis in original) Hewlett-Pack-
ard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 
USPQ2d 1525, 1528 (Fed. Cir. 1990). 

MANNER OF OPERATING THE DEVICE DOES 
NOT DIFFERENTIATE APPARATUS CLAIM FROM 
THE PRIOR ART

A claim containing a "recitation with respect to the man-
ner in which a claimed apparatus is intended to be 
employed does not differentiate the claimed apparatus from 
a prior art apparatus" if the prior art apparatus teaches all 
the structural limitations of the claim. Ex parte Masham, 2 
USPQ2d 1647 (Bd. Pat. App. & Inter. 1987) (The preamble 
of claim 1 recited that the apparatus was "for mixing flow-
ing developer material" and the body of the claim recited 
"means for mixing ..., said mixing means being stationary 
and completely submerged in the developer material". The 
claim was rejected over a reference which taught all the 
structural limitations of the claim for the intended use of 
mixing flowing developer. However, the mixer was only 
partially submerged in the developer material. The Board 
held that the amount of submersion is immaterial to the 
structure of the mixer and thus the claim was properly 
rejected.). 

A PRIOR ART DEVICE CAN PERFORM ALL THE 
FUNCTIONS OF THE APPARATUS CLAIM AND 
STILL NOT ANTICIPATE THE CLAIM

Even if the prior art device performs all the functions 
recited in the claim, the prior art cannot anticipate the claim 
if there is any structural difference. It should be noted, 
however, that means plus function limitations are met by 
structures which are equivalent to the corresponding struc-
tures recited in the specification. In re Ruskin, 347 F.2d 
843, 146 USPQ 211 (CCPA 1965) as implicitly modified 
by   In re Donaldson, 16 F.3d 1189, 29 USPQ2d 1845 (Fed. 
Cir. 1994).  >See also In re Robertson, 169 F.3d 743, 745, 
49 USPQ2d 1949, 1951 (Fed. Cir. 1999)(The claims were 
drawn to a disposable diaper having three fastening ele-
ments. The reference disclosed two fastening elements that 
could perform the same function as the three fastening ele-
ments in the claims. The court construed the claims to 
require three separate elements and held that the reference 
did not disclose a separate third fastening element, either 
expressly or inherently.).<

2115	Material or Article Worked Upon by 
Apparatus

MATERIAL OR ARTICLE WORKED UPON DOES 
NOT LIMIT APPARATUS CLAIMS 

"Expressions relating the apparatus to contents thereof 
during an intended operation are of no significance in 
determining patentability of the apparatus claim." Ex parte 
Thibault, 164 USPQ 666, 667 (Bd. App. 1969). Further-
more, "Inclusion of material or article worked upon by a 
structure being claimed does not impart patentability to the 
claims." In re Young, 75 F.2d 966, 25 USPQ 69 (CCPA 
1935) (as restated in   In re Otto, 312 F.2d 937, 136 USPQ 
458, 459 (CCPA 1963)).

In   In re Young, a claim to a machine for making con-
crete beams included a limitation to the concrete reinforced 
members made by the machine as well as the structural ele-
ments of the machine itself. The court held that the inclu-
sion of the article formed within the body of the claim did 
not, without more, make the claim patentable.

In   In re Casey, 370 F.2d 576, 152 USPQ 235 (CCPA 
1967), an apparatus claim recited "A taping machine com-
prising a supporting structure, a brush attached to said sup-
porting structure, said brush being formed with projecting 
bristles which terminate in free ends to collectively define a 
surface to which adhesive tape will detachably adhere, and 
means for providing relative motion between said brush 
and said supporting structure while said adhesive tape is 
adhered to said surface." An obviousness rejection was 
made over a reference to Kienzle which taught a machine 
for perforating sheets. The court upheld the rejection stat-
ing that "the references in claim 1 to adhesive tape handling 
do not expressly or impliedly require any particular struc-
ture in addition to that of Kienzle." The perforating device 
had the structure of the taping device as claimed, the differ-
ence was in the use of the device, and "the manner or 
method in which such machine is to be utilized is not ger-
mane to the issue of patentability of the machine itself."

Note that this line of cases is limited to claims directed 
to machinery which works upon an article or material in its 
intended use, it does not apply to product claims or kit 
claims (i.e., claims directed to a plurality of articles 
grouped together as a kit). 

2116	Material Manipulated in Process

The materials on which a process is carried out must be 
accorded weight in determining the patentability of a pro-
cess. Ex parte Leonard, 187 USPQ 122 (Bd. App. 1974).

2116.01	Novel, Unobvious Starting Material 
or End Product

All the limitations of a claim must be considered when 
weighing the differences between the claimed invention 
and the prior art in determining the obviousness of a pro-
cess or method claim.  See  MPEP ? 2143.03.

In re Ochiai, 71 F.3d 1565, 37 USPQ2d 1127 (Fed. Cir. 
1995) and In re Brouwer, 77 F.3d 422, 37 USPQ2d 1663 
(Fed. Cir. 1996) addressed the issue of whether an other-
wise conventional process could be patented if it were lim-
ited to making or using a nonobvious product.  In both 
cases, the Federal Circuit held that the use of per se rules is 
improper in applying the test for obviousness under  35 
U.S.C. 103.  Rather,  35 U.S.C. 103 requires a highly fact-
dependent analysis involving taking the claimed subject 
matter as a whole and comparing it to the prior art.  To sup-
port a rejection under  35 U.S.C. 103, the collective teach-
ings of the prior art must have suggested to one of ordinary 
skill in the art that, at the time the invention was made, 
applicant's claimed invention would have been obvious.  In 
applying this test to the claims on appeal in Ochiai and 
Brouwer, the court held that there simply was no sugges-
tion or motivation in the prior art to make or use novel, 
nonobvious products in the claimed processes.  Conse-
quently, the court overturned the rejections based upon  35 
U.S.C. 103.

Interpreting the claimed invention as a whole requires 
consideration of all claim limitations.  Thus, proper claim 
construction requires treating language in a process claim 
which recites the making or using of a nonobvious product 
as a material limitation. Motivation to make or use the non-
obvious product must be present in the prior art for a 
35 U.S.C. 103 rejection to be sustained. The decision in 
Ochiai specifically dispelled any distinction between pro-
cesses of making a product and methods of using a product 
with regard to the effect of any product limitations in either 
type of claim.

As noted in Brouwer, 77 F.3d at 425, 37 USPQ2d at 
1666, the inquiry as to whether a claimed invention would 
have been obvious is "highly fact-specific by design".  
Accordingly, obviousness must be assessed on a case-by-
case basis.  The following decisions are illustrative of the 
lack of   per se rules in applying the test for obviousness 
under 35 U.S.C. 103 and of the fact intensive comparison 
of claimed processes with the prior art: In re Durden, 763 
F.2d 1406, 226 USPQ 359 (Fed. Cir. 1985) (The examiner 
rejected a claim directed to a process in which patentable 
starting materials were reacted to form patentable end prod-
ucts. The prior art showed the same chemical reaction 
mechanism applied to other chemicals.  The court held that 
the process claim was obvious over the prior art.); In re 
Albertson, 332 F.2d 379, 141 USPQ 730 (CCPA 1964)(Pro-
cess of chemically reducing one novel, nonobvious mate-
rial to obtain another novel, nonobvious material was 
claimed.  The process was held obvious because the reduc-
tion reaction was old.); In re Kanter, 399 F.2d 249, 158 
USPQ 331 (CCPA 1968) (Process of siliconizing a patent-
able base material to obtain a patentable product was 
claimed. Rejection based on prior art teaching the siliconiz-
ing process as applied to a different base material was 
upheld.); Cf. In re Pleuddemann, 910 F.2d 823, 15 USPQ2d 
1738 (Fed. Cir. 1990) (Methods of bonding polymer and 
filler using a novel silane coupling agent held patentable 
even though methods of bonding using other silane cou-
pling agents were well known because the process could 
not be conducted without the new agent); In re Kuehl, 475 
F.2d 658, 177 USPQ 250 (CCPA 1973) (Process of crack-
ing hydrocarbons using novel zeolite catalyst found to be 
patentable even though catalytic cracking process was old. 
"The test under  103 is whether in view of the prior art the 
invention as a whole would have been obvious at the time it 
was made, and the prior art here does not include the zeo-
lite, ZK-22.  The obviousness of the process of cracking 
hydrocarbons with ZK-22 as a catalyst must be determined 
without reference to knowledge of ZK-22 and its proper-
ties."  475 F.2d at 664-665, 177 USPQ at 255.); and In re 
Mancy, 499 F.2d 1289, 182 USPQ 303 (CCPA 1974) 
(Claim to a process for the production of a known antibiotic 
by cultivating a novel, unobvious microorganism was 
found to be patentable.). 

2121	Prior Art; General Level of 
Operability Required to Make a Prima 
Facie Case

PRIOR ART IS PRESUMED TO BE OPERABLE/ 
ENABLING

When the reference relied on expressly anticipates or 
makes obvious all of the elements of the claimed invention, 
the reference is presumed to be operable. Once such a refer-
ence is found, the burden is on applicant to provide facts 
rebutting the presumption of operability. In re Sasse, 629 
F.2d 675, 207 USPQ 107 (CCPA 1980). See also MPEP 
? 716.07.

WHAT CONSTITUTES AN "ENABLING DISCLO-
SURE" DOES NOT DEPEND ON THE TYPE OF 
PRIOR ART THE DISCLOSURE IS CONTAINED IN

The level of disclosure required within a reference to 
make it an "enabling disclosure" is the same no matter what 
type of prior art is at issue. It does not matter whether the 
prior art reference is a U.S. patent, foreign patent, a printed 
publication or other. There is no basis in the statute 
(35 U.S.C. 102 or 103) for discriminating either in favor of 
or against prior art references on the basis of nationality. In 
re Moreton, 288 F.2d 708, 129 USPQ 227 (CCPA 1961).

2121.01	Use of Prior Art in Rejections 
Where Operability Is in Question

"In determining that quantum of prior art disclosure 
which is necessary to declare an applicant's invention `not 
novel' or `anticipated' within section 102, the stated test is 
whether a reference contains an `enabling disclosure'... ."  
In re Hoeksema, 399 F.2d 269, 158 USPQ 596 (CCPA 
1968). A reference contains an "enabling disclosure" if the 
public was in possession of the claimed invention before 
the date of invention. "Such possession is effected if one of 
ordinary skill in the art could have combined the publica-
tion's description of the invention with his [or her] own 
knowledge to make the claimed invention." In re Donohue, 
766 F.2d 531, 226 USPQ 619 (Fed. Cir. 1985).

I.	35 U.S.C. 102 REJECTIONS AND ADDITION 
OF EVIDENCE SHOWING REFERENCE IS 
OPERABLE

It is possible to make a 35 U.S.C. 102 rejection even if 
the reference does not itself teach one of ordinary skill how 
to practice the invention, i.e., how to make or use the article 
disclosed. If the reference teaches every claimed element of 
the article, secondary evidence, such as other patents or 
publications, can be cited to show public possession of the 
method of making and/or using. In re Donohue, 766 F.2d at 
533, 226 USPQ at 621. See MPEP ? 2131.01 for more 
information on 35 U.S.C. 102 rejections using secondary 
references to show that the primary reference contains an 
"enabling disclosure." 

II.	35 U.S.C. 103 REJECTIONS AND USE OF 
INOPERATIVE PRIOR ART

"Even if a reference discloses an inoperative device, it is 
prior art for all that it teaches." Beckman Instruments v. 
LKB Produkter AB, 892 F.2d 1547, 1551, 13 USPQ2d 
1301, 1304 (Fed. Cir. 1989). Therefore, "a non-enabling 
reference may qualify as prior art for the purpose of deter-
mining obviousness under  35 U.S.C. 103." Symbol Tech-
nologies Inc. v. Opticon Inc., 935 F.2d 1569, 1578, 19 
USPQ2d 1241, 1247 (Fed. Cir. 1991).

2121.02	Compounds and Compositions - 
What Constitutes Enabling Prior  
Art

ONE OF ORDINARY SKILL IN THE ART MUST BE 
ABLE TO MAKE OR SYNTHESIZE

Where a process for making the compound is not devel-
oped until after the date of invention, the mere naming of a 
compound in a reference, without more, cannot constitute a 
description of the compound. In re Hoeksema, 399 F.2d 
269, 158 USPQ 596 (CCPA 1968). Note, however, that a 
reference is presumed operable until applicant provides 
facts rebutting the presumption of operatibility. In re Sasse, 
629 F.2d 675, 207 USPQ 107 (CCPA 1980). Therefore, 
applicant must provide evidence showing that a process for 
making was not known at the time of the invention. See the 
following paragraph for the evidentiary standard to be 
applied. 

A REFERENCE DOES NOT CONTAIN AN 
"ENABLING DISCLOSURE" IF ATTEMPTS AT 
MAKING THE COMPOUND OR COMPOSITION 
WERE UNSUCCESSFUL BEFORE THE DATE OF 
INVENTION

When a prior art reference merely discloses the structure 
of the claimed compound, evidence showing that attempts 
to prepare that compound were unsuccessful before the 
date of invention will be adequate to show inoperability. In 
re Wiggins, 488 F.2d 538, 179 USPQ 421 (CCPA 1971). 
However, the fact that an author of a publication did not 
attempt to make the compound disclosed, without more, 
will not overcome a rejection based on that publication. In 
re Donohue, 766 F.2d 531, 226 USPQ 619 (Fed. Cir. 1985) 
(In this case, the examiner had made a rejection 
under 35 U.S.C. 102(b) over a publication, which disclosed 
the claimed compound, in combination with two patents 
teaching a general process of making the particular class of 
compounds. The applicant submitted an affidavit stating 
that the authors of the publication had not actually synthe-
sized the compound. The court held that the fact that the 
publication's author did not synthesize the disclosed com-
pound was immaterial to the question of reference operabil-
ity. The patents were evidence that synthesis methods were 
well known. The court distinguished Wiggins, in which a 
very similar rejection was reversed. In Wiggins, attempts to 
make the compounds using the prior art methods were all 
unsuccessful.). Compare   In re Hoeksema, 399 F.2d 269, 
158 USPQ 596 (CCPA 1968) (A claim to a compound was 
rejected over a patent to De Boer which disclosed com-
pounds similar in structure to those claimed (obvious 
homologs) and a process of making these compounds. 
Applicant responded with an affidavit by an expert named 
Wiley which stated that there was no indication in the De 
Boer patent that the process disclosed in De Boer could be 
used to produce the claimed compound and that he did not 
believe that the process disclosed in De Boer could be 
adapted to the production of the claimed compound. The 
court held that the facts stated in this affidavit were legally 
sufficient to overcome the rejection and that applicant need 
not show that all known processes are incapable of produc-
ing the claimed compound for this showing would be prac-
tically impossible.). 

2121.03	Plant Genetics - What Constitutes 
Enabling Prior Art

THOSE OF ORDINARY SKILL MUST BE ABLE TO 
GROW AND CULTIVATE THE PLANT

When the claims are drawn to plants, the reference, com-
bined with knowledge in the prior art, must enable one of 
ordinary skill in the art to reproduce the plant. In re LeG-
rice, 301 F.2d 929, 133 USPQ 365 (CCPA 1962) (National 
Rose Society Annual of England and various other cata-
logues showed color pictures of the claimed roses and dis-
closed that applicant had raised the roses. The publications 
were published more than 1 year before applicant's filing 
date. The court held that the publications did not place the 
rose in the public domain. Information on the grafting pro-
cess required to reproduce the rose was not included in the 
publications and such information was necessary for those 
of ordinary skill in the art (plant breeders) to reproduce the 
rose.). Compare Ex parte Thompson, 24 USPQ2d 1618 
(Bd. Pat. App. & Inter. 1992) (Seeds were commercially 
available more than 1 year prior to applicant's filing date. 
One of ordinary skill in the art could grow the claimed cot-
ton cultivar from the commercially available seeds. Thus, 
the publications describing the cotton cultivar had "enabled 
disclosures." The Board distinguished In re LeGrice by 
finding that the catalogue picture of the rose of In re LeG-
rice was the only evidence in that case. There was no evi-
dence of commercial availability in enabling form since the 
asexually reproduced rose could not be reproduced from 
seed. Therefore, the public would not have possession of 
the rose by its picture alone, but the public would have pos-
session of the cotton cultivar based on the publications and 
the availability of the seeds.).

2121.04	Apparatus and Articles - What 
Constitutes Enabling Prior Art

PICTURES MAY CONSTITUTE AN "ENABLING 
DISCLOSURE"

Pictures and drawings may be sufficiently enabling to 
put the public in the possession of the article pictured. 
Therefore, such an enabling picture may be used to reject 
claims to the article. However, the picture must show all the 
claimed structural features and how they are put together. 
Jockmus v. Leviton, 28 F.2d 812 (2d Cir. 1928). See also  
MPEP ? 2125 for a discussion of drawings as prior art. 

2122	Discussion of Utility in the Prior Art 

UTILITY NEED NOT BE DISCLOSED IN REFER-
ENCE

In order to constitute anticipatory prior art, a reference 
must identically disclose the claimed compound, but no 
utility need be disclosed by the reference. In re Schoen-
wald, 964 F.2d 1122, 22 USPQ2d 1671 (Fed. Cir. 1992) 
(The application claimed compounds used in ophthalmic 
compositions to treat dry eye syndrome. The examiner 
found a printed publication which disclosed the claimed 
compound but did not disclose a use for the compound. The 
court found that the claim was anticipated since the com-
pound and a process of making it was taught by the refer-
ence. The court explained that "no utility need be disclosed 
for a reference to be anticipatory of a claim to an old com-
pound." 964 F.2d at 1124, 22 USPQ2d at 1673. It is enough 
that the claimed compound is taught by the reference.).

2123	Rejection Over Prior Art's Broad 
Disclosure Instead of Preferred 
Embodiments [R-1]

PATENTS ARE RELEVANT AS PRIOR ART FOR 
ALL THEY CONTAIN

"The use of patents as references is not limited to what 
the patentees describe as their own inventions or to the 
problems with which they are concerned. They are part of 
the literature of the art, relevant for all they contain." In re 
Heck, 699 F.2d 1331, 1332-33, 216 USPQ 1038, 1039 
(Fed. Cir. 1983) (quoting   In re Lemelson, 397 F.2d 1006, 
1009, 158 USPQ 275, 277 (CCPA 1968)). 

A reference may be relied upon for all that it would have 
reasonably suggested to one having ordinary skill the art, 
including nonpreferred embodiments. Merck & Co. v. 
Biocraft Laboratories, 874 F.2d 804, 10 USPQ2d 1843 
(Fed. Cir.), cert. denied, 493 U.S. 975 (1989).  >See also 
Celeritas Technologies Ltd. v. Rockwell International 
Corp., 150 F.3d 1354, 1361, 47 USPQ2d 1516, 1522-23 
(Fed. Cir. 1998)(The court held that the prior art anticipated 
the claims even though it taught away from the claimed 
invention. "The fact that a modem with a single carrier data 
signal is shown to be less than optimal does not vitiate the 
fact that it is disclosed.").<

NONPREFERRED EMBODIMENTS CONSTITUTE 
PRIOR ART

Disclosed examples and preferred embodiments do not 
constitute a teaching away from a broader disclosure or 
nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 
USPQ 423 (CCPA 1971). "A known or obvious composi-
tion does not become patentable simply because it has been 
described as somewhat inferior to some other product for 
the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 
1130, 1132 (Fed. Cir. 1994) (The invention was directed to 
* an epoxy impregnated fiber-reinforced printed circuit 
material. The applied prior art reference taught a printed 
circuit material similar to that of the claims but impreg-
nated with polyester-imide resin instead of epoxy. The ref-
erence, however, disclosed that epoxy was known for this 
use, but that epoxy impregnated circuit boards have "rela-
tively acceptable dimensional stability" and "some degree 
of flexibility," but are inferior to circuit boards impregnated 
with polyester-imide resins. The court upheld the rejection 
concluding that, while the reference did teach away from 
using epoxy, the "teaching away" was insufficient to over-
come the rejection since "Gurley asserted no discovery 
beyond what was known in the art." 27 F.3d at 554, 31 
USPQ2d at 1132.). 

2124	Exception to the Rule That the 
Critical Reference Date Must Precede 
the Filing Date

IN SOME CIRCUMSTANCES A FACTUAL REFER-
ENCE NEED NOT ANTEDATE THE FILING DATE

In certain circumstances, references cited to show a uni-
versal fact need not be available as prior art before appli-
cant's filing date. In re Wilson, 311 F.2d 266, 135 USPQ 
442 (CCPA 1962). Such facts include the characteristics 
and properties of a material or a scientific truism. Some 
specific examples in which later publications showing fac-
tual evidence can be cited include situations where the facts 
shown in the reference are evidence "that, as of an applica-
tion's filing date, undue experimentation would have been 
required,   In re Corneil, 347 F.2d 563, 568, 145 USPQ 702, 
705 (CCPA 1965), or that a parameter absent from the 
claims was or was not critical, In re Rainer, 305 F.2d 505, 
507 n.3, 134 USPQ 343, 345 n.3 (CCPA 1962), or that a 
statement in the specification was inaccurate, In re Marzoc-
chi, 439 F.2d 220, 223 n.4, 169 USPQ 367, 370 n.4 (CCPA 
1971), or that the invention was inoperative or lacked util-
ity, In re Langer, 503 F.2d 1380, 1391, 183 USPQ 288, 297 
(CCPA 1974), or that a claim was indefinite, In re Glass, 
492 F.2d 1228,1232 n.6, 181 USPQ 31, 34 n.6 (CCPA 
1974), or that characteristics of prior art products were 
known, In re Wilson, 311 F.2d 266, 135 USPQ 442 (CCPA 
1962)." In re Koller, 613 F.2d 819, 823 n.5, 204 USPQ 702, 
706 n.5 (CCPA 1980) (quoting In re Hogan, 559 F.2d 595, 
605 n.17, 194 USPQ 527, 537 n.17 (CCPA 1977) (empha-
sis in original)). However, it is impermissible to use a later 
factual reference to determine whether the application is 
enabled or described as required under 35 U.S.C. 112, first 
paragraph. In re Koller, 613 F.2d 819, 823 n. 5, 204 USPQ 
702, 706 n.5 (CCPA 1980). References which do not qual-
ify as prior art because they postdate the claimed invention 
may be relied upon to show the level of ordinary skill in the 
art at or around the time the invention was made. Ex parte 
Erlich, 22 USPQ 1463 (Bd. Pat. App. & Inter. 1992).

2125	Drawings as Prior Art

DRAWINGS CAN BE USED AS PRIOR ART

Drawings and pictures can anticipate claims if they 
clearly show the structure which is claimed. In re Mraz, 
455 F.2d 1069, 173 USPQ 25 (CCPA 1972). However, the 
picture must show all the claimed structural features and 
how they are put together. Jockmus v. Leviton, 28 F.2d 812 
(2d Cir. 1928). The origin of the drawing is immaterial. For 
instance, drawings in a design patent can anticipate or make 
obvious the claimed invention as can drawings in utility 
patents. When the reference is a utility patent, it does not 
matter that the feature shown is unintended or unexplained 
in the specification. The drawings must be evaluated for 
what they reasonably disclose and suggest to one of ordi-
nary skill in the art. In re Aslanian, 590 F.2d 911, 200 
USPQ 500 (CCPA 1979). See MPEP ? 2121.04 for more 
information on prior art drawings as "enabled disclosures."

PROPORTIONS OF FEATURES IN A DRAWING 
ARE NOT EVIDENCE OF ACTUAL PROPORTIONS 
WHEN DRAWINGS ARE NOT TO SCALE

When the reference does not disclose that the drawings 
are to scale and is silent as to dimensions, arguments based 
on measurement of the drawing features are of little value. 
However, the description of the article pictured can be 
relied on, in combination with the drawings, for what they 
would reasonably teach one of ordinary skill in the art. In re 
Wright, 569 F.2d 1124, 193 USPQ 332 (CCPA 1977) ("We 
disagree with the Solicitor's conclusion, reached by a com-
parison of the relative dimensions of appellant's and 
Bauer's drawing figures, that Bauer `clearly points to the 
use of a chime length of roughly 1/2 to 1 inch for a whiskey 
barrel.' This ignores the fact that Bauer does not disclose 
that his drawings are to scale. ... However, we agree with 
the Solicitor that Bauer's teaching that whiskey losses are 
influenced by the distance the liquor needs to `traverse the 
pores of the wood' (albeit in reference to the thickness of 
the barrelhead)" would have suggested the desirability of 
an increased chime length to one of ordinary skill in the art 
bent on further reducing whiskey losses." 569 F.2d at 1127, 
193 USPQ at 335-36.) 

2126	Availability of a Document as a 
"Patent" for Purposes of Rejection 
Under 35 U.S.C. 102(a), (b), and (d) 

THE NAME "PATENT" ALONE DOES NOT MAKE 
A DOCUMENT AVAILABLE AS A PRIOR ART 
PATENT UNDER 35 U.S.C. 102(a) or (b)

What a foreign country designates to be a patent may not 
be a patent for purposes of rejection under 35 U.S.C. 102(a) 
and (b); it is the substance of the rights conferred and the 
way information within the "patent" is controlled that is 
determinative. In re Ekenstam, 256 F.2d 321, 118 USPQ 
349 (CCPA 1958). See the next paragraph for further expla-
nation with respect to when a document can be applied in a 
rejection as a "patent." See  MPEP ? 2135.01 for a further 
discussion of the use of "patents" in 35 U.S.C. 102(d) 
rejections.

A SECRET PATENT IS NOT AVAILABLE AS A 
REFERENCE UNDER 35 U.S.C. 102(a) or (b) UNTIL 
IT IS AVAILABLE TO THE PUBLIC BUT IT MAY BE 
AVAILABLE UNDER 35 U.S.C. 102(d) AS OF GRANT 
DATE 

Secret patents are defined as patents which are insuffi-
ciently accessible to the public to constitute "printed publi-
cations." Decisions on the issue of what is sufficiently 
accessible to be a "printed publication" are located in  
MPEP ? 2128 -  ? 2128.01.

Even if a patent grants an exclusionary right (is enforce-
able), it is not available as prior art under  35 U.S.C. 102(a) 
or (b) if it is secret or private. In re Carlson, 983 F.2d 1032, 
1037, 25 USPQ2d 1207, 1211 (Fed. Cir. 1992). The docu-
ment must be at least minimally available to the public to 
constitute prior art. The patent is sufficiently available to 
the public for the purposes of  35 U.S.C. 102(a) or (b) if it 
is laid open for public inspection or disseminated in printed 
form.  See, e.g., In re Carlson, 938 F.2d at 1037, 25 
USPQ2d at 1211 ("We recognize that   Geschmacksmuster 
on display for public view in remote cities in a far-away 
land may create a burden of discovery for one without the 
time, desire, or resources to journey there in person or by 
agent to observe that which was registered under German 
law. Such a burden, however, is by law imposed upon the 
hypothetical person of ordinary skill in the art who is 
charged with knowledge of all contents of the relevant prior 
art."). The date that the patent is made available to the pub-
lic is the date it is available as a  35 U.S.C. 102(a) or (b) 
reference. In re Ekenstam, 256 F.2d 321, 118 USPQ 349 
(CCPA 1958). But a period of secrecy after granting the 
patent has been held to have no effect in connection with 35 
U.S.C. 102(d). These patents are usable in rejections under  
35 U.S.C. 102(d) as of the date patent rights are granted. In 
re Kathawala, 9 F.3d 942, 28 USPQ2d 1789 (Fed. Cir. 
1993).  See  MPEP ? 2135 -  ? 2135.01 for more informa-
tion on  35 U.S.C. 102(d). 

2126.01	Date of Availability of a Patent As a  
Reference 

DATE FOREIGN PATENT IS EFFECTIVE AS A 
REFERENCE IS USUALLY THE DATE PATENT 
RIGHTS ARE FORMALLY AWARDED TO ITS 
APPLICANT 

The date the patent is available as a reference is gener-
ally the date that the patent becomes enforceable. This date 
is the date the sovereign formally bestows patents rights to 
the applicant. In re Monks, 588 F.2d 308, 200 USPQ 129 
(CCPA 1978). There is an exception to this rule when the 
patent is secret as of the date the rights are awarded. In re 
Ekenstam, 256 F.2d 321, 118 USPQ 349 (CCPA 1958). 

Note that  MPEP ? 901.05 summarizes in tabular form 
dates of patenting for many foreign patents. Chisum, Pat-
ents ? 3.06[4] n.2 gives a good summary of decisions 
which specify reference availability dates for specific 
classes of foreign patents. A copy of Chisum is kept in the 
law library of the Solicitor's Office and in the Lutrelle F. 
Parker, Sr., Memorial Law Library located in CPK1-520.

2126.02	Scope of Reference's Disclosure  
Which Can Be Used to Reject  
Claims When the Reference Is a  
"Patent" but Not a "Publication" 

OFTEN UNCLAIMED DETAILS FOUND IN THE 
PATENT SPECIFICATION CAN BE RELIED ON 
EVEN IF PATENT IS SECRET

When the patented document is used as a patent and not 
as a publication, the examiner is not restricted to the infor-
mation conveyed by the patent claims but may use any 
information provided in the specification which relates to 
the subject matter of the patented claims when making a 
rejection under 35 U.S.C. 102(a), (b) or (d). Ex parte Ovist, 
152 USPQ 709, 710 (Bd. App. 1963) (The claim of an Ital-
ian patent was generic and thus embraced the species dis-
closed in the examples, the Board added that the entire 
specification was germane to the claimed invention and 
upheld the examiner's 35 U.S.C. 102(b) rejection.); In re 
Kathawala, 9 F.3d 942, 28 USPQ2d 1785 (Fed. Cir. 1993) 
(The claims at issue where rejected under  35 U.S.C. 102(d) 
by applicant's own parent applications in Greece and Spain. 
The applicant argued that the "invention ... patented' in 
Spain was not the same `invention' claimed in the U.S. 
application because the Spanish patent claimed processes 
for making [compounds for inhibition of cholesterol bio-
synthesis] and claims 1 and 2 were directed to the com-
pounds themselves." 9 F.3d at 944, 28 USPQ2d at 1786. 
The Federal Circuit held that "when an applicant files a for-
eign application fully disclosing his invention and having 
the potential to claim his invention in a number of ways, 
the reference in section 102(d) to `invention ... patented' 
necessarily includes all disclosed aspects of the invention."  
9 F.3d at 945-46, 28 USPQ2d at 1789.)

In re Fuge, 272 F.2d 954, 957, 124 USPQ 105, 107 
(CCPA 1959), does not conflict with the above decisions. 
This decision simply states "that, at the least, the scope of 
the patent embraces everything included in the [claim]." 
(emphasis added). 

Note that the courts have interpreted the phrase "inven-
tion ... patented" in 102(a), (b), and (d) the same way and 
have cited decisions without regard to which of these sub-
sections of 35 U.S.C. 102 was at issue in the particular case 
at hand. Therefore, it does not seem to matter to which sub-
section of 102 the cases are directed; the court decisions are 
interchangeable as to this issue. 

2127	Domestic and Foreign Patent  
Applications as Prior Art  [R-1]

I.	ABANDONED APPLICATIONS, INCLUDING 
PROVISIONAL APPLICATIONS

Abandoned Applications Disclosed to the Public Can Be 
Used as Prior Art

"An abandoned patent application may become evidence 
of prior art only when it has been appropriately disclosed, 
as, for example, when the abandoned patent [application] is 
reference[d] in the disclosure of another patent, in a publi-
cation, or by voluntary disclosure under [fomer Defensive 
Publication rule]  37 CFR 1.139."   Lee Pharmaceutical v. 
Kreps, 577 F.2d 610, 613, 198 USPQ 601, 605 (9th Cir. 
1978). An abandoned patent application becomes available 
as prior art only as of the date the public gains access to it. 
See  37 CFR 1.14(a)(3)(iv).  However, the subject matter of 
an abandoned application, including both provisional and 
nonprovisional applications, referred to in a prior art U.S. 
patent may be relied on in a 35 U.S.C. 102(e) rejection 
based on that patent if the disclosure of the abandoned 
application is actually included or incorporated by refer-
ence in the patent. Compare In re Lund, 376 F.2d 982, 991, 
153 USPQ 625, 633 (CCPA 1967) (The court reversed a 
rejection over a patent which was a continuation-in-part of 
an abandoned application. Applicant's filing date preceded 
the issue date of the patent reference. The abandoned appli-
cation contained subject matter which was essential to the 
rejection but which was not carried over into the continua-
tion-in-part. The court held that the subject matter of the 
abandoned application was not available to the public as of 
either the parent's or the child's filing dates and thus could 
not be relied on in the 102(e) rejection.). See also  MPEP ? 
901.02. See  MPEP ? 2136.02 and  ? 2136.03 for the 
35 U.S.C. 102(e) date of a U.S. patent claiming priority 
under  35 U.S.C. 119 or 120.

II.	APPLICATIONS WHICH HAVE ISSUED INTO 
U.S. PATENTS

A 35 U.S.C. 102(e) Rejection Cannot Rely on Matter 
Which Was Canceled from the Application and Thus Did 
Not Get Published in the Issued Patent

Canceled matter in the application file of a U.S. patent 
cannot be relied upon in a rejection under 35 U.S.C. 102(e). 
Ex Parte Stalego, 154 USPQ 52, 53 (Bd. App. 1966). The 
canceled matter only becomes available as prior art as of 
the date the application issues into a patent since this is the 
date the application file wrapper becomes available to the 
public. In re Lund, 376 F.2d 982, 153 USPQ 625 (CCPA 
1967). For more information on available prior art for use 
in 35 U.S.C. 102(e) rejections see  MPEP ? 2136.02.

III.	FOREIGN APPLICATIONS OPEN FOR PUB-
LIC INSPECTION (LAID OPEN APPLICA-
TIONS) 

Laid Open Applications May Constitute "Published" 
Documents

When the specification is not issued in printed form but 
is announced in an official journal and anyone can inspect 
or obtain copies, it is sufficiently accessible to the public to 
constitute a "publication" within the meaning of 35 U.S.C. 
102(a) and (b). See   In re Wyer, 655 F.2d 221, 210 USPQ 
790 (CCPA 1981). 

Older cases have held that laid open patent applications 
are not "published" and cannot constitute prior art. Ex parte 
Haller, 103 USPQ 332 (Bd. App. 1953). However, whether 
or not a document is "published" for the purposes of  35 
U.S.C. 102 and 103 depends on how accessible the docu-
ment is to the public. As technology has made reproduction 
of documents easier, the accessibility of the laid open appli-
cations has increased. Items provided in easily reproducible 
form have thus become "printed publications" as the phrase 
is used in 35 U.S.C. 102. In re Wyer, 655 F.2d 221, 226, 210 
USPQ 790, 794 (CCPA 1981) (Laid open Australian patent 
application held to be a "printed publication" even though 
only the abstract was published because it was laid open for 
public inspection, microfilmed, "diazo copies" were dis-
tributed to five suboffices having suitable reproduction 
equipment and the diazo copies were available for sale.). 
The contents of a foreign patent application should not be 
relied upon as prior art until the date of publication (i.e., the 
insertion into the laid open application) can be confirmed 
by an examiner's review of a copy of the document.  See  
MPEP ? 901.05.

IV.	PENDING U.S. APPLICATIONS

As specified in  37 CFR 1.14(a), all pending U.S. appli-
cations are preserved in confidence except for reissue 
applications and applications in which a request to open the 
complete application to inspection by the public has been 
granted by the Office (37 CFR 1.11(b)). However, if two 
copending applications have a common assignee or inven-
tor, a rejection will be proper in some circumstances. For 
instance, when the claims between the two applications are 
not independent or distinct, a provisional double patenting 
rejection is made. See  MPEP ? 804. If the copending appli-
cations differ by at least one inventor and at least one of the 
applications *>would have been< obvious in view of the 
other, a provisional rejection over  35 U.S.C. 102(e) or 103 
is made >when appropriate<. See  MPEP ? 706.02(f) *>,<  
? 706.02(k) >,  ? 706.02(l)(1), and ? 706.02(l)(3)<.

2128	"Printed Publications" as Prior Art  
[R-1]

A REFERENCE IS A "PRINTED PUBLICATION" IF 
IT IS ACCESSIBLE TO THE PUBLIC

A reference is proven to be a "printed publication" 
"upon a satisfactory showing that such document has been 
disseminated or otherwise made available to the extent that 
persons interested and ordinarily skilled in the subject mat-
ter or art, exercising reasonable diligence, can locate it." In 
re Wyer, 655 F.2d 221, 210 USPQ 790 (CCPA 1981) (quot-
ing I.C.E. Corp. v. Armco Steel Corp., 250 F. Supp. 738, 
743, 148 USPQ 537, 540 (SDNY 1966)) ("We agree that 
`printed publication' should be approached as a unitary 
concept. The traditional dichotomy between `printed' and 
`publication' is no longer valid. Given the state of technol-
ogy in document duplication, data storage, and data 
retrieval systems, the `probability of dissemination' of an 
item very often has little to do with whether or not it is 
`printed' in the sense of that word when it was introduced 
into the patent statutes in 1836. In any event, interpretation 
of the words `printed' and `publication' to mean `probabil-
ity of dissemination' and `public accessibility' respectively, 
now seems to render their use in the phrase `printed publi-
cation' somewhat redundant.") In re Wyer, 655 F.2d at 226, 
210 USPQ at 794.

See also Carella v. Starlight Archery, 804 F.2d 135, 231 
USPQ 644 (Fed. Cir. 1986) (Starlight Archery argued that 
Carella's patent claims to an archery sight were anticipated 
under  35 U.S.C. 102(a) by an advertisement in a Wiscon-
sin Bow Hunter Association (WBHA) magazine and a 
WBHA mailer prepared prior to Carella's filing date. How-
ever, there was no evidence as to when the mailer was 
received by any of the addressees. Plus, the magazine had 
not been mailed until 10 days after Carella's filing date. 
The court held that since there was no proof that either the 
advertisement or mailer was accessible to any member of 
the public before the filing date there could be no rejection 
under  35 U.S.C. 102(a).). 

>ELECTRONIC PUBLICATIONS AS PRIOR ART

Status as a "Printed Publication"

 An electronic publication, including an on-line database 
or Internet publication, is considered to be a "printed publi-
cation" within the meaning of 35 U.S.C. 102(a) and (b) 
provided the publication was accessible to persons con-
cerned with the art to which the document relates. 
See In re Wyer, 655 F.2d 221, 227, 210 USPQ 790, 
795 (CCPA 1981)("Accordingly, whether information is 
printed, handwritten, or on microfilm or a magnetic disc or 
tape, etc., the one who wishes to characterize the informa-
tion, in whatever form it may be, as a `printed publication'  
* * * should produce sufficient proof of its dissemination or 
that it has otherwise been available and accessible to per-
sons concerned with the art to which the document relates 
and thus most likely to avail themselves of its contents.' " 
(citations omitted).). See also Amazon.com v. Barnesandno-
ble.com, 73 F. Supp. 2d 1228, 53 USPQ2d 1115, 1119 
(W.D. Wash. 1999)(Pages from a website were relied on by 
defendants as an anticipatory reference (to no avail), how-
ever status of the reference as prior art was not chal-
lenged.); In re Epstein, 32 F.3d 1559, 31 USPQ2d 1817 
(Fed. Cir. 1994)(Database printouts of abstracts which were 
not themselves prior art publications were properly relied 
as providing evidence that the software products referenced 
therein were "first installed" or "released" more than one 
year prior to applicant's filing date.).

The Office policy requiring recordation of the field of 
search and search results (see MPEP ? 719.05) weighs in 
favor of finding that Internet and on-line database refer-
ences cited by the examiner are "accessible to persons con-
cerned with the art to which the document relates and thus 
most likely to avail themselves of its contents." Wyer, 655 
F.2d at 221, 210 USPQ at 790. Office copies of an elec-
tronic document must be retained if the same document 
may not be available for retrieval in the future. This is espe-
cially important for sources such as the Internet and online 
databases.

Date of Availability 

 Prior art disclosures on the Internet or on an on-line 
database are considered to be publicly available as of the 
date the item was publicly posted. If the publication does 
not include a publication date (or retrieval date), it cannot 
be relied upon as prior art under 35 U.S.C. 102(a) or (b), 
although it may be relied upon to provide evidence regard-
ing the state of the art. 

Extent of Teachings Relied Upon 

 An electronic publication, like any publication, may be 
relied upon for all that it would have reasonably suggested 
to one having ordinary skill in the art. See MPEP 
? 2121.01and ? 2123. Note, however, that if an electronic 
document which is the abstract of a patent or printed publi-
cation is relied upon in a rejection under 35 U.S.C. 102 or  
103, only the text of the abstract (and not the underlying 
document) may be relied upon to support the rejection. In 
situations where the electronic version and the published 
paper version of the same or a corresponding patent or 
printed publication differ appreciably, each may need to be 
cited and relied upon as independent references based on 
what they disclose. 

Internet Usage Policy

 See MPEP ?  904.02(c) for the portions of the Internet 
Usage Policy pertaining to Internet searching and docu-
menting search strategies. See MPEP ? 707.05 for the 
proper citation of electronic documents.<  

EXAMINER NEED NOT PROVE ANYONE ACTU-
ALLY LOOKED AT THE DOCUMENT

One need not prove someone actually looked at a publi-
cation when that publication is accessible to the public 
through a library or patent office. See In re Wyer, 655 F.2d 
221, 210 USPQ 790 (CCPA 1981); In re Hall, 781 F.2d 
897, 228 USPQ 453 (Fed. Cir. 1986).

2128.01	Level of Public Accessibility  
Required [R-1]

A THESIS PLACED IN A UNIVERSITY LIBRARY 
MAY BE PRIOR ART IF SUFFICIENTLY ACCESSI-
BLE TO THE PUBLIC

A doctoral thesis indexed and shelved in a library is suf-
ficiently accessible to the public to constitute prior art as a 
"printed publication." In re Hall, 781 F.2d 897, 228 USPQ 
453 (Fed. Cir. 1986). Even if access to the library is 
restricted, a reference will constitute a "printed publica-
tion" as long as a presumption is raised that the portion of 
the public concerned with the art would know of the inven-
tion. In re Bayer, 568 F.2d 1357, 196 USPQ 670 (CCPA 
1978).

In   In re Hall, general library cataloging and shelving 
practices showed that a doctoral thesis deposited in univer-
sity library would have been indexed, cataloged and 
shelved and thus available to the public before the critical 
date. Compare   In re Cronyn, 890 F.2d 1158, 13 USPQ2d 
1070 (Fed. Cir.1989) *>wherein doctoral< theses were 
shelved and indexed by index cards filed alphabetically by 
student name and kept in a shoe box in the chemistry 
library. The index cards only listed the student name and 
title of the thesis. Two of three judges held that the students' 
theses were not accessible to the public. The court reasoned 
that the theses had not been either cataloged or indexed in a 
meaningful way since thesis could only be found if the 
researcher's name was known, but the name bears no rela-
tionship to the subject of the thesis. One judge, however, 
held that the fact that the theses were shelved in the library 
was enough to make them sufficiently accessible to the 
public. The nature of the index was not determinative. 
This judge relied on prior Board decisions (Gulliksen v. 
Halberg, 75 USPQ 252, 257 (Bd. App. 1937) and Ex parte 
Hershberger, 96 USPQ 54, 56 (Bd. App. 1952)), which 
held that shelving a single copy in a public library makes 
the work a "printed publication." It should be noted that 
these Board decisions have not been expressly overruled 
but have been criticized in other decisions. See In re Ten-
ney, 254 F.2d 619, 117 USPQ 348 (CCPA 1958) (concur-
ring opinion by J.Rich) (A document, of which there is but 
one copy, whether it be handwritten, typewritten or on 
microfilm, may be technically accessible to anyone who 
can find it. Such a document is not "printed" in the sense 
that a printing press has been used to reproduce the docu-
ment. If only technical accessibility were required "logic 
would require the inclusion within the term [printed] of all 
unprinted public documents for they are all `accessible.' 
While some tribunals have gone quite far in that direction, 
as in the `college thesis cases' I feel they have done so 
unjustifiably and on the wrong theory. Knowledge is not in 
the possession of the public where there has been no dis-
semination, as distinguished from technical accessibility..." 
The real significance of the word "printed" is grounded in 
the "probability of wide circulation."). See also Deep Weld-
ing, Inc. v. Sciaky Bros., 417 F.2d 1227, 163 USPQ 144 (7th 
Cir. 1969) (calling the holding of Ex parte Hershberger 
"extreme"). Compare In re Bayer, 568 F.2d 1357, 196 
USPQ 670 (CCPA 1978) (A reference will constitute a 
"printed publication" as long as a presumption is raised that 
the portion of the public concerned with the art would 
know of the invention even if accessibility is restricted to 
only this part of the public. But accessibility to applicant's 
thesis was restricted to only three members of a graduate 
committee. There can be no presumption that those con-
cerned with the art would have known of the invention in 
this case.).

ORALLY PRESENTED PAPER CAN CONSTITUTE 
A "PRINTED PUBLICATION" IF WRITTEN COP-
IES ARE AVAILABLE WITHOUT RESTRICTION

A paper which is orally presented in a forum open to all 
interested persons constitutes a "printed publication" if 
written copies are disseminated without restriction. Massa-
chusetts Institute of Technology v. AB Fortia, 774 F.2d 
1104, 1109, 227 USPQ 428, 432 (Fed. Cir. 1985) (Paper 
orally presented to between 50 and 500 persons at a scien-
tific meeting open to all persons interested in the subject 
matter, with written copies distributed without restriction to 
all who requested, is a printed publication. Six persons 
requested and obtained copies.).

INTERNAL DOCUMENTS INTENDED TO BE CON-
FIDENTIAL ARE NOT "PRINTED PUBLICATIONS"

Documents and items only distributed internally within 
an organization which are intended to remain confidential 
are not "printed publications" no matter how many copies 
are distributed. In re George, 2 USPQ2d 1880 (Bd. Pat. 
App. & Inter. 1987) (Research reports disseminated in-
house to only those persons who understood the policy of 
confidentiality regarding such reports are not printed publi-
cations even though the policy was not specifically stated 
in writing.); Garret Corp. v. United States, 422 F.2d 874, 
878, 164 USPQ 521, 524 (Ct. Cl.1970) ("While distribution 
to government agencies and personnel alone may not con-
stitute publication ... distribution to commercial companies 
without restriction on use clearly does."); Northern Tele-
com Inc. v. Datapoint Corp., 908 F.2d 931, 15 USPQ2d 
1321 (Fed. Cir. 1990) (Four reports on the AESOP-B mili-
tary computer system which were not under security classi-
fication were distributed to about fifty organizations 
involved in the AESOP-B project. One document contained 
the legend "Reproduction or further dissemination is not 
authorized." The other documents were of the class that 
would contain this legend. The documents were housed in 
Mitre Corporation's library. Access to this library was 
restricted to those involved in the AESOP-B project. The 
court held that public access was insufficient to make the 
documents "printed publications.").

2128.02	Date Publication Is Available as a 
Reference 

DATE OF ACCESSIBILITY CAN BE SHOWN 
THROUGH EVIDENCE OF ROUTINE BUSINESS 
PRACTICES

Evidence showing routine business practices can be used 
to establish the date on which a publication became acces-
sible to the public. Specific evidence showing when the 
specific document actually became available is not always 
necessary. Constant v. Advanced Micro-Devices, Inc., 848 
F.2d 1560, 7 USPQ2d 1057 (Fed. Cir.), cert. denied, 988 
U.S. 892 (1988) (Court held that evidence submitted by 
Intel regarding undated specification sheets showing how 
the company usually treated such specification sheets was 
enough to show that the sheets were accessible by the pub-
lic before the critical date.); In re Hall, 781 F.2d 897, 228 
USPQ 453 (Fed. Cir. 1986) (Librarian's affidavit establish-
ing normal time frame and practice for indexing, cataloging 
and shelving doctoral theses established that the thesis in 
question would have been accessible by the public before 
the critical date.). 

A JOURNAL ARTICLE OR OTHER PUBLICATION 
BECOMES AVAILABLE AS PRIOR ART ON DATE 
OF IT IS RECEIVED BY A MEMBER OF THE 
PUBLIC

A publication disseminated by mail is not prior art until 
it is received by at least one member of the public. Thus, a 
magazine or technical journal is effective as of its date of 
publication (date when first person receives it) not the date 
it was mailed or sent to the publisher. In re Schlittler, 234 
F.2d 882, 110 USPQ 304 (CCPA 1956). 

2129	Admissions as Prior Art  [R-1]

ADMISSIONS BY APPLICANT CONSTITUTE 
PRIOR ART

When applicant states that something is prior art, it is 
taken as being available as prior art against the claims. 
Admitted prior art can be used in obviousness rejections. In 
re Nomiya, 509 F.2d 566, 184 USPQ 607, 610 (CCPA 
1975) (Figures in the application labeled "prior art" held to 
be an admission that what was pictured was prior art rela-
tive to applicant's invention.). 

A JEPSON CLAIM RESULTS IN AN IMPLIED 
ADMISSION THAT PREAMBLE IS PRIOR ART

The preamble elements in a Jepson-type claim (i.e., a 
claim of the type discussed in  37 CFR 1.75(e); see MPEP 
? 608.01(m)) "are impliedly admitted to be old in the art, ... 
but it is only an implied admission." In re Ehrreich, 590 
F.2d 902, 909-910 200 USPQ 504, 510 (CCPA 1979) 
(emphasis in original) (citations omitted). See also Sjolund 
v. Musland, 847 F.2d 1573, 1577, 6 USPQ2d 2020, 2023 
(Fed. Cir. 1988); Pentec, Inc. v. Graphic Controls Corp., 
776 F.2d 309, 315, 227 USPQ 766, 770 (Fed. Cir. 1985); 
and Reading & Bates Construction Co. v. Baker Energy 
Resources Corp., 748 F.2d 645, 650, 223 USPQ 1168, 1172 
(Fed. Cir. 1984). Claims must be read in light of the specifi-
cation. Where the specification confirms that the subject 
matter of the preamble was invented by another before 
applicant's invention, the preamble is treated as prior art. 
However, certain art may be prior art to one inventive 
entity, but not to the public in general. In re Fout, 675 F.2d 
297, 300-301, 213 USPQ 532, 535-36 (CCPA 1982). This 
is the case when applicant has made an improvement on his 
or her own prior invention. An applicant's own founda-
tional work should not, unless there is a statutory bar, be 
treated as prior art solely because knowledge of this work is 
admitted. Therefore, when applicant explains that the   Jep-
son format is being used to avoid a double patenting rejec-
tion over *>the applicant's< own copending application, 
the implication that the *>preamble< is admitted prior art is 
overcome. Reading & Bates Construction Co. v. Baker 
Energy Resources Corp., 748 F.2d 645, 650, 223 USPQ 
1168, 1172 (Fed. Cir. 1984). Compare In re Fout, 675 F.2d 
297, 300-01, 213 USPQ 532, 535-36 (CCPA 1982) (The 
court held that the preamble was admitted prior art because 
the specification explained that Paglaro, a different inven-
tor, had invented the subject matter described in the pream-
ble.).

2131	Anticipation - Application of 35 U.S.C.  
102(a), (b), and (e)  [R-1]

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

(a)	the invention was known or used by others in this country, or 
patented or described in a printed publication in this or a foreign country, 
before the invention thereof by the applicant for a patent, or

(b)	the invention was patented or described in a printed publication 
in this or a foreign country or in public use or on sale in this country, more 
than one year prior to the date of application for patent in the United 
States, or

(c)	he has abandoned the invention, or

(d)	the invention was first patented or caused to be patented, or was 
the subject of an inventor's certificate, by the applicant or his legal repre-
sentatives or assigns in a foreign country prior to the date of the applica-
tion for patent in this country on an application for patent or inventor's 
certificate filed more than twelve months before the filing of the applica-
tion in the United States, or 

(e)	the invention was described in a patent granted on an applica-
tion for patent by another filed in the United States before the invention 
thereof by the applicant for patent, or on an international application by 
another who has fulfilled the requirements of paragraphs (1), (2), and (4) 
of section 371(c) of this title before the invention thereof by the applicant 
for patent, or

(f)	he did not himself invent the subject matter sought to be pat-
ented, or **

>

(g)(1)	 during the course of an interference conducted under section 
135 or section 291, another inventor involved therein establishes, to the 
extent permitted in section 104, that before such person's invention 
thereof the invention was made by such other inventor and not abandoned, 
suppressed, or concealed, or (2) before such person's invention thereof, 
the invention was made in this country by another inventor who had not 
abandoned, suppressed, or concealed it. In determining priority of inven-
tion under this subsection, there shall be considered not only the respec-
tive dates of conception and reduction to practice of the invention, but also 
the reasonable diligence of one who was first to conceive and last to 
reduce to practice, from a time prior to conception by the other.<

TO ANTICIPATE A CLAIM, THE REFERENCE 
MUST TEACH EVERY ELEMENT OF THE CLAIM

"A claim is anticipated only if each and every element as 
set forth in the claim is found, either expressly or inherently 
described, in a single prior art reference." Verdegaal Bros. 
v. Union Oil Co. of California, 814 F.2d 628, 631, 2 
USPQ2d 1051, 1053 (Fed. Cir. 1987). "The identical inven-
tion must be shown in as complete detail as is contained in 
the ... claim." Richardson v. Suzuki Motor Co., 868 F.2d 
1226, 1236, 9 USPQ2d 1913, 1920 (Fed. Cir. 1989). The 
elements must be arranged as required by the claim, but 
this is not an   ipsissimis verbis test, i.e., identity of termi-
nology is not required. In re Bond, 910 F.2d 831, 15 
USPQ2d 1566 (Fed. Cir. 1990). Note that, in some circum-
stances, it is permissible to use multiple references in a 
35 U.S.C. 102 rejection. See  MPEP ? 2131.01.

2131.01	Multiple Reference 35 U.S.C. 102 
Rejections  [R-1]

Normally, only one reference should be used in making a 
rejection under 35 U.S.C. 102. However, a 35 U.S.C. 102 
rejection over multiple references has been held to be 
proper when the extra references are cited to:

(A)	Prove the primary reference contains an "enabled 
disclosure;" 

(B)	Explain the meaning of a term used in the primary 
reference; or 

(C)	Show that a characteristic not disclosed in the ref-
erence is inherent. 

See paragraphs I-III below for more explanation of each 
circumstance.

I.	TO PROVE REFERENCE CONTAINS AN 
"ENABLED DISCLOSURE"

Extra References and Extrinsic Evidence Can Be Used To 
Show the Primary Reference Contains an "Enabled 
Disclosure"

When the claimed composition or machine is disclosed 
identically by the reference, an additional reference may be 
relied on to show that the primary reference has an 
"enabled disclosure." In re Samour, 571 F.2d 559, 197 
USPQ 1 (CCPA 1978) and In re Donohue, 766 F.2d 531, 
226 USPQ 619 (Fed. Cir. 1985) (Compound claims were 
rejected under  35 U.S.C. 102(b) over a publication in view 
of two patents. The publication disclosed the claimed com-
pound structure while the patents taught methods of mak-
ing compounds of that general class. The applicant argued 
that there was no motivation to combine the references 
because no utility was previously known for the compound 
and that the 35 U.S.C. 102 rejection over multiple refer-
ences was improper. The court held that the publication 
taught all the elements of the claim and thus motivation to 
combine was not required. The patents were only submitted 
as evidence of what was in the public's possession before 
applicant's invention.). 

II.	TO EXPLAIN THE MEANING OF A TERM 
USED IN THE PRIMARY REFERENCE

Extra References or Other Evidence Can Be Used to 
Show Meaning of a Term Used in the Primary Reference

Extrinsic evidence may be used to explain but not 
expand the meaning of terms and phrases used in the refer-
ence relied upon as anticipatory of the claimed subject mat-
ter. In re Baxter Travenol Labs., 952 F.2d 388, 21 USPQ2d 
1281 (Fed. Cir. 1991) (Baxter Travenol Labs. invention 
was directed to a blood bag system incorporating a bag 
containing DEHP, an additive to the plastic which 
improved the bag's red blood cell storage capability. The 
examiner rejected the claims over a technical progress 
report by Becker which taught the same blood bag system 
but did not expressly disclose the presence of DEHP. The 
report, however, did disclose using commercial blood bags. 
It also disclosed the blood bag system as "very similar to 
[Baxter] Travenol's commercial two bag blood container." 
Extrinsic evidence (depositions, declarations and   Baxter 
Travenol's own admissions) showed that commercial blood 
bags, at the time Becker's report was written, contained 
DEHP. Therefore, one of ordinary skill in the art would 
have known that "commercial blood bags" meant bags con-
taining DEHP. The claims were thus held to be antici-
pated.).

III.	TO SHOW THAT A CHARACTERISTIC NOT 
DISCLOSED IN THE REFERENCE IS INHER-
ENT 

Extra Reference or Evidence Can Be Used To Show an 
Inherent Characteristic of the Thing Taught by the 
Primary Reference

"To serve as an anticipation when the reference is silent 
about the asserted inherent characteristic, such gap in the 
reference may be filled with recourse to extrinsic evidence. 
Such evidence must make clear that the missing descriptive 
matter is necessarily present in the thing described in the 
reference, and that it would be so recognized by persons of 
ordinary skill." Continental Can Co. USA v. Monsanto Co., 
948 F.2d 1264, 1268, 20 USPQ2d 1746, 1749 (Fed. Cir. 
1991) (The court went on to explain that "this modest flexi-
bility in the rule that `anticipation' requires that every ele-
ment of the claims appear in a single reference 
accommodates situations in which the common knowledge 
of technologists is not recorded in the reference; that is, 
where technological facts are known to those in the field of 
the invention, albeit not known to judges." 948 F.2d at 
1268, 20 USPQ at 1749-50.) Note that **>as long as there 
is evidence of record establishing inherency, failure of 
those skilled in the art to contemporaneously recognize an 
inherent property, function or ingredient of a prior art refer-
ence does not preclude a finding of anticipation. Atlas Pow-
der Co. v. IRECO, Inc., 190 F.3d 1342, 1349, 51 USPQ2d 
1943, 1948 (Fed. Cir. 1999)(Two prior art references dis-
closed blasting compositions containing water-in-oil emul-
sions with identical ingredients to those claimed, 
in overlapping ranges with the claimed composition. The 
only element of the claims arguably not present in the 
prior art compositions was "sufficient aeration . . . 
entrapped to enhance sensitivity to a substantial degree." 
The Federal Circuit found that the emulsions described 
in both references would inevitably and inherently have 
"sufficient aeration" to sensitize the compound in the 
claimed ranges based on the evidence of record (including 
test data and expert testimony). This finding of inherency 
was not defeated by the fact that one of the references 
taught away from air entrapment or purposeful aeration.). 
See also In re King, 801 F.2d 1324, 1327, 231 USPQ 136, 
139 (Fed. Cir. 1986); Titanium Metals Corp. v. Banner, 778 
F.2d 775, 782, 227 USPQ 773, 778 (Fed. Cir. 1985).<  See  
MPEP ? 2112 -  ? 2112.02 for case law on inherency. Also 
note that the critical date of extrinsic evidence showing a 
universal fact need not antedate the filing date.  See  MPEP  
? 2124. 

2131.02	Genus-Species Situations 

A SPECIES WILL ANTICIPATE A CLAIM TO A 
GENUS

"A generic claim cannot be allowed to an applicant if the 
prior art discloses a species falling within the claimed 
genus." The species in that case will anticipate the genus. 
In re Slayter, 276 F.2d 408, 411, 125 USPQ 345, 347 
(CCPA 1960); In re Gosteli, 872 F.2d 1008, 10 USPQ2d 
1614 (Fed. Cir. 1989) (Gosteli claimed a genus of 21 spe-
cific chemical species of bicyclic thia-aza compounds in 
Markush claims. The prior art reference applied against the 
claims disclosed two of the chemical species. The parties 
agreed that the prior art species would anticipate the claims 
unless applicant was entitled to his foreign priority date.).

A REFERENCE THAT CLEARLY NAMES THE 
CLAIMED SPECIES ANTICIPATES THE CLAIM 
NO MATTER HOW MANY OTHER SPECIES ARE 
NAMED

A genus does not always anticipate a claim to a species 
within the genus. However, when the species is clearly 
named, the species claim is anticipated no matter how 
many other species are additionally named. Ex parte A, 17 
USPQ2d 1716 (Bd. Pat. App. & Inter. 1990) (The claimed 
compound was named in a reference which also disclosed 
45 other compounds. The Board held that the comprehen-
siveness of the listing did not negate the fact that the com-
pound claimed was specifically taught. The Board 
compared the facts to the situation in which the compound 
was found in the Merck Index, saying that "the tenth edition 
of the Merck Index lists ten thousand compounds. In our 
view, each and every one of those compounds is `described' 
as that term is used in 35 U.S.C. ? 102(a), in that publica-
tion.").  Id. at 1718.  See also   In re Sivaramakrishnan, 673 
F.2d 1383, 213 USPQ 441 (CCPA 1982) (The claims were 
directed to polycarbonate containing cadmium laurate as an 
additive. The court upheld the Board's finding that a refer-
ence specifically naming cadmium laurate as an additive 
amongst a list of many suitable salts in polycarbonate resin 
anticipated the claims. The applicant had argued that cad-
mium laurate was only disclosed as representative of the 
salts and was expected to have the same properties as the 
other salts listed while, as shown in the application, cad-
mium laurate had unexpected properties. The court held 
that it did not matter that the salt was not disclosed as being 
preferred, the reference still anticipated the claims and 
because the claim was anticipated, the unexpected proper-
ties were immaterial.).

A GENERIC CHEMICAL FORMULA WILL ANTIC-
IPATE A CLAIMED SPECIES COVERED BY THE 
FORMULA WHEN THE SPECIES CAN BE "AT 
ONCE ENVISAGED" FROM THE FORMULA

When the compound is not specifically named, but 
instead it is necessary to select portions of teachings within 
a reference and combine them, e.g., select various substitu-
ents from a list of alternatives given for placement at spe-
cific sites on a generic chemical formula to arrive at a 
specific composition, anticipation can only be found if the 
classes of substituents are sufficiently limited or well delin-
eated. Ex parte A, 17 USPQ2d 1716 (Bd. Pat. App. & Inter. 
1990). If one of ordinary skill in the art is able to "at once 
envisage" the specific compound within the generic chemi-
cal formula, the compound is anticipated. One of ordinary 
skill in the art must be able to draw the structural formula 
or write the name of each of the compounds included in the 
generic formula before any of the compounds can be "at 
once envisaged." One may look to the preferred embodi-
ments to determine which compounds can be anticipated. 
In re Petering, 301 F.2d 676, 133 USPQ 275 (CCPA 1962).

In In re Petering, the prior art disclosed a generic chemi-
cal formula "wherein X, Y, Z, P, and R'- represent either 
hydrogen or alkyl radicals, R a side chain containing an OH 
group."  The court held that this formula, without more, 
could not anticipate a claim to 7-methyl-9-[d, l'-ribityl]-
isoalloxazine because the generic formula encompassed a 
vast number and perhaps even an infinite number of com-
pounds. However, the reference also disclosed preferred 
substituents for X, Y, Z, R, and R' as follows: where X, P, 
and R' are hydrogen, where Y and Z may be hydrogen or 
methyl, and where R is one of eight specific isoalloxazines. 
The court determined that this more limited generic class 
consisted of about 20 compounds. The limited number of 
compounds covered by the preferred formula in combina-
tion with the fact that the number of substituents was low at 
each site, the ring positions were limited, and there was a 
large unchanging structural nucleus, resulted in a finding 
that the reference sufficiently described "each of the vari-
ous permutations here involved as fully as if he had drawn 
each structural formula or had written each name." The 
claimed compound was 1 of these 20 compounds. There-
fore, the reference "described" the claimed compound and 
the reference anticipated the claims.

In In re Schauman, 572 F.2d 312, 197 USPQ 5 (CCPA 
1978), claims to a specific compound were anticipated 
because the prior art taught a generic formula embracing a 
limited number of compounds closely related to each other 
in structure and the properties possessed by the compound 
class of the prior art was that disclosed for the claimed 
compound. The broad generic formula seemed to describe 
an infinite number of compounds but claim 1 was limited to 
a structure with only one variable substituent R. This sub-
stituent was limited to low alkyl radicals. One of ordinary 
skill in the art would at once envisage the subject matter 
within claim 1 of the reference.). 

Compare In re Meyer, 599 F.2d 1026, 202 USPQ 175 
(CCPA 1979) (A reference disclosing "alkaline chlorine or 
bromine solution" embraces a large number of species and 
cannot be said to anticipate claims to "alkali metal 
hypochlorite."); Akzo N.V. v. International Trade Comm'n, 
808 F.2d 1471, 1 USPQ2d 1241 (Fed. Cir. 1986) (Claims to 
a process for making aramid fibers using a 98% solution of 
sulfuric acid were not anticipated by a reference which dis-
closed using sulfuric acid solution but which did not dis-
close using a 98% concentrated sulfuric acid solution.). See  
MPEP ? 2144.08 for a discussion of obviousness in genus-
species situations.

2131.03	Anticipation of Ranges 

A SPECIFIC EXAMPLE IN THE PRIOR ART 
WHICH IS WITHIN A CLAIMED RANGE ANTICI-
PATES THE RANGE

"[W]hen, as by a recitation of ranges or otherwise, a 
claim covers several compositions, the claim is `antici-
pated' if one of them is in the prior art." Titanium Metals 
Corp. v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 
1985) (citing In re Petering, 301 F.2d 676, 682, 133 USPQ 
275, 280 (CCPA 1962))(emphasis in original) (Claims to 
titanium (Ti) alloy with 0.6-0.9% nickel (Ni) and 0.2-0.4% 
molybdenum (Mo) were held anticipated by a graph in a 
Russian article on Ti-Mo-Ni alloys because the graph con-
tained an actual data point corresponding to a Ti alloy con-
taining 0.25% Mo and 0.75% Ni and this composition was 
within the claimed range of compositions.).

PRIOR ART WHICH TEACHES A RANGE WITHIN, 
OVERLAPPING, OR TOUCHING THE CLAIMED 
RANGE ANTICIPATES IF THE PRIOR ART RANGE 
DISCLOSES THE CLAIMED RANGE WITH 
"SUFFICIENT SPECIFICITY"

When the prior art discloses a range which touches, 
overlaps or is within the claimed range, but no specific 
examples falling within the claimed range are disclosed, a 
case by case determination must be made as to anticipation. 
In order to anticipate the claims, the claimed subject matter 
must be disclosed in the reference with "sufficient specific-
ity to constitute an anticipation under the statute." What 
constitutes a "sufficient specificity" is fact dependent. If the 
claims are directed to a narrow range, the reference teaches 
a broad range, and there is evidence of unexpected results 
within the claimed narrow range, depending on the other 
facts of the case, it may be reasonable to conclude that the 
narrow range is not disclosed with "sufficient specificity" 
to constitute an anticipation of the claims. The unexpected 
results may also render the claims unobvious.  The question 
of "sufficient specificity" is similar to that of "clearly 
envisaging" a species from a generic teaching. See  MPEP 
? 2131.02. A 35 U.S.C. 102/103 combination rejection is 
permitted if it is unclear if the reference teaches the range 
with "sufficient specificity." The examiner must, in this 
case, provide reasons for anticipation as well as a motiva-
tional statement regarding obviousness. Ex parte Lee 31 
USPQ2d 1105 (Bd. Pat. App. & Inter. 1993) (expanded 
Board). For a discussion of the obviousness of ranges see  
MPEP ? 2144.05.

2131.04	Secondary Considerations 

Evidence of secondary considerations, such as unex-
pected results or commercial success, is irrelevant to 
35 U.S.C. 102 rejections and thus cannot overcome a rejec-
tion so based. In re Wiggins, 488 F.2d 538, 543, 179 USPQ 
421, 425 (CCPA 1973).

2131.05	Nonanalogous Art  [R-1]

"Arguments that the alleged anticipatory prior art is 
`nonanalogous art' or `teaches away from the invention' or 
is not recognized as solving the problem solved by the 
claimed invention, [are] not `germane' to a rejection under 
section 102." Twin Disc, Inc. v. United  States, 231 USPQ 
417, 424 (Cl. Ct. 1986) (quoting In re Self, 671 F.2d 1344, 
213 USPQ 1, 7 (CCPA 1982)).

>A reference is no less anticipatory if, after disclosing 
the invention, the reference then disparages it. The question 
whether a reference "teaches away" from the invention is 
inapplicable to an anticipation analysis. Celeritas Technol-
ogies Ltd. v. Rockwell International Corp., 150 F.3d 1354, 
1361, 47 USPQ2d 1516, 1522-23 (Fed. Cir. 1998)(The 
prior art was held to anticipate the claims even though it 
taught away from the claimed invention. "The fact that a 
modem with a single carrier data signal is shown to be less 
than optimal does not vitiate the fact that it is disclosed."). 
See also Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342, 
1349, 51 USPQ2d 1943, 1948 (Fed. Cir. 1999)(Claimed 
composition was anticipated by prior art reference that 
inherently met claim limitation of "sufficient aeration" 
even though reference taught away from air entrapment or 
purposeful aeration.).<

2132	35 U.S.C. 102(a) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

(a)	the invention was known or used by others in this country, or 
patented or described in a printed publication in this or a foreign country, 
before the invention thereof by the applicant for a patent.

*****

I.	"KNOWN OR USED"

"Known or Used" Means Publicly Known or Used

"The statutory language `known or used by others in this 
country' (35 U.S.C. ? 102(a)), means knowledge or use 
which is accessible to the public." Carella v. Starlight 
Archery, 804 F.2d 135, 231 USPQ 644 (Fed. Cir. 1986). 
The knowledge or use is accessible to the public if there has 
been no deliberate attempt to keep it secret. W. L. Gore & 
Assoc. v. Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 
(Fed. Cir. 1983).

See  MPEP ? 2128 -  ? 2128.02 for case law concerning 
public accessibility of publications. 

Another's Sale of a Product Made by a Secret Process 
Can Be a 35 U.S.C. 102(a) Public Use if the Process Can 
Be Determined by Examining the Product

"The nonsecret use of a claimed process in the usual 
course of producing articles for commercial purposes is a 
public use." But a secret use of the process coupled with 
the sale of the product does not result in a public use of the 
process unless the public could learn the claimed process 
by examining the product. Therefore, secret use of a pro-
cess by another, even if the product is commercially sold, 
cannot result in a rejection under 35 U.S.C. 102(a) if an 
examination of the product would not reveal the process.   
Id.

II.	"IN THIS COUNTRY"

Only Knowledge or Use in the U.S. Can Be Used in a 
35 U.S.C. 102(a) Rejection

The knowledge or use relied on in a 35 U.S.C. 102(a) 
rejection must be knowledge or use "in this country." Prior 
knowledge or use which is not present in the United States, 
even if widespread in a foreign country, cannot be the basis 
of a rejection under 35 U.S.C. 102(a). In re Ekenstam, 256 
F.2d 321, 118 USPQ 349 (CCPA 1958). Note that the 
changes made to 35 U.S.C. 104 by NAFTA (Public Law 
103-182) and Uruguay Round Agreements Act (Public 
Law 103-465) do not modify the meaning of "in this coun-
try" as used in 35 U.S.C. 102(a) and thus "in this country" 
still means in the United States for purposes of 35 U.S.C. 
102(a) rejections. 

III.	"BY OTHERS"

"Others" Means Any Combination of Authors or 
Inventors Different Than the Inventive Entity

The term "others" in 35 U.S.C. 102(a) refers to any 
entity which is different from the inventive entity. The 
entity need only differ by one person to be "by others." 
This holds true for all types of references eligible as prior 
art under 35 U.S.C. 102(a) including publications as well as 
public knowledge and use. Any other interpretation of 35 
U.S.C. 102(a) "would negate the one year [grace] period 
afforded under ? 102(b)." In re Katz, 687 F.2d 450, 215 
USPQ 14 (CCPA 1982).

IV.	"PATENTED IN THIS OR A FOREIGN  COUN-
TRY"

See  MPEP ? 2126 for information on the use of secret 
patents as prior art.

2132.01	Publications as 35 U.S.C. 102(a) 
Prior Art 

35 U.S.C. 102(a) PRIMA FACIE CASE IS 
ESTABLISHED IF REFERENCE PUBLICATION IS 
"BY OTHERS"

A prima facie case is made out under 35 U.S.C. 102(a) 
if, within 1 year of the filing date, the invention, or an obvi-
ous variant thereof, is described in a "printed publication" 
whose authorship differs in any way from the inventive 
entity unless it is stated within the publication itself that the 
publication is describing the applicant's work. In re Katz, 
687 F.2d 450, 215 USPQ 14 (CCPA 1982). See MPEP 
? 2128 for case law on what constitutes a "printed publica-
tion." Note that when the reference is a U.S. patent pub-
lished within the year prior to the application filing date, a  
35 U.S.C. 102(e) rejection should be made. See MPEP 
? 2136 - ? 2136.05 for case law dealing with 102(e).

APPLICANT CAN REBUT PRIMA FACIE CASE BY 
SHOWING REFERENCE'S DISCLOSURE WAS 
DERIVED FROM APPLICANT'S OWN WORK

Applicant's disclosure of his or her own work within the 
year before the application filing date cannot be used 
against him or her under  35 U.S.C. 102(a). In re Katz, 687 
F.2d 450, 215 USPQ 14 (CCPA 1982) (discussed below). 
Therefore, where the applicant is one of the co-authors of a 
publication cited against his or her application, the publica-
tion may be removed as a reference by the filing of affida-
vits made out by the other authors establishing that the 
relevant portions of the publication originated with, or were 
obtained from, applicant. Such affidavits are called dis-
claiming affidavits.   Ex parte Hirschler, 110 USPQ 384 
(Bd. App. 1952). The rejection can also be overcome by 
submission of a specific declaration by the applicant estab-
lishing that the article is describing applicant's own work.   
In re Katz, 687 F.2d 450, 215 USPQ 14 (CCPA 1982). 
However, if there is evidence that the co-author has refused 
to disclaim inventorship and believes himself or herself to 
be an inventor, applicant's affidavit will not be enough to 
establish that applicant is the sole inventor and the rejection 
will stand. Ex parte Kroger, 219 USPQ 370 (Bd. Pat. App. 
& Int. 1982) (discussed below). It is also possible to over-
come the rejection by adding the coauthors as inventors to 
the application if the requirements of 35 U.S.C. 116, third 
paragraph are met.   In re Searles, 422 F.2d 431, 164 USPQ 
623 (CCPA 1970).

In   In re Katz, 687 F.2d 450, 215 USPQ 14 (CCPA 
1982), Katz stated in a declaration that the coauthors of the 
publication, Chiorazzi and Eshhar, "were students working 
under the direction and supervision of the inventor, Dr. 
David H. Katz." The court held that this declaration, in 
combination with the fact that the publication was a 
research paper, was enough to establish Katz as the sole 
inventor and that the work described in the publication was 
his own. In research papers, students involved only with 
assay and testing are normally listed as coauthors but are 
not considered co-inventors.

In Ex parte Kroger, 219 USPQ 370 (Bd. Pat. App. & 
Inter. 1982), Kroger, Knaster and others were listed as 
authors on an article on photovoltaic power generation. The 
article was used to reject the claims of an application listing 
Kroger  and  Rod as inventors. Kroger and Rod submitted 
affidavits declaring themselves to be the inventors. The 
affidavits also stated that Knaster merely carried out 
assignments and worked under the supervision and direc-
tion of Kroger. The Board stated that if this were the only 
evidence in the case, it would be established, under In re 
Katz, that Kroger and Rod were the only inventors. How-
ever, in this case, there was evidence that Knaster had 
refused to sign an affidavit disclaiming inventorship and 
Knaster had introduced evidence into the case in the form 
of a letter to the PTO in which he alleged that he was a co-
inventor. The Board held that the evidence had not been 
fully developed enough to overcome the rejection. Note 
that the rejection had been made under 35 U.S.C. 102(f) but 
the Board treated the issue the same as if it had arisen under  
35 U.S.C. 102(a). See also case law dealing with overcom-
ing 102(e) rejections as presented in MPEP ? 2136.05. 
Many of the issues are the same.

A RULE 131 AFFIDAVIT CAN BE USED TO 
OVERCOME A 35 U.S.C. 102(a) REJECTION

When the reference is not a statutory bar under 
35 U.S.C. 102(b), (c), or (d), applicant can overcome the 
rejection by swearing back of the reference through the 
submission of an affidavit under 37 CFR 1.131. In re Fos-
ter, 343 F.2d 980, 145 USPQ 166 (CCPA 1965). If the ref-
erence is disclosing applicant's own work as derived from 
him or her, applicant may submit either a 37 CFR 1.131 
affidavit to antedate the reference or a 37 CFR 1.132 affida-
vit to show derivation of the reference subject matter from 
applicant and invention by applicant. In re Facius, 408 F.2d 
1396, 161 USPQ 294 (CCPA 1969). See MPEP ? 715 for 
more information on when an affidavit under 37 CFR 1.131 
can be used to overcome a reference and what evidence is 
required.

2133	35 U.S.C. 102(b) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

(b)	the invention was patented or described in a printed publication 
in this or a foreign country or in public use or on sale in this country, more 
than one year prior to the date of application for patent in the United 
States.

*****

THE 1-YEAR GRACE PERIOD IS EXTENDED TO 
THE NEXT WORKING DAY IF IT WOULD OTHER-
WISE END ON A HOLIDAY OR WEEKEND

Publications, patents, public uses and sales must occur 
"more than one year prior to the date of application for 
patent in the United States" in order to bar a patent under  
35 U.S.C. 102(b). However, applicant's own activity will 
not bar a patent if the 1-year grace period expires on a Sat-
urday, Sunday, or Federal holiday and the application's 
U.S. filing date is the next succeeding business day. Ex 
parte Olah, 131 USPQ 41 (Bd. App. 1960). Despite 
changes to  37 CFR 1.6(a)(2) and 1.10 which require the 
PTO to accord a filing date to an application as of the date 
of deposit as "Express Mail" with the U.S. Postal Service in 
accordance with  37 CFR 1.10 (e.g., a Saturday filing date), 
the rule changes do not affect applicant's concurrent right to 
defer the filing of an application until the next business day 
when the last day for "taking any action" falls on a Satur-
day, Sunday, or a Federal holiday (e.g., the last day of the 1-
year grace period falls on a Saturday).

THE 1-YEAR TIME BAR IS MEASURED FROM 
THE U.S. FILING DATE

If one discloses his or her own work more than 1  year 
before the filing of the patent application, that person is 
barred from obtaining a patent. In re Katz, 687 F.2d 450, 
454, 215 USPQ 14, 17 (CCPA 1982). The 1-year time bar 
is measured from the U.S. filing date. Thus, applicant will 
be barred from obtaining a patent if the public came into 
possession of the invention on a date before the 1-year 
grace period ending with the U.S. filing date. It does not 
matter how the public came into possession of the inven-
tion. Public possession could occur by a public use, public 
sale, a publication, a patent or any combination of these. In 
addition, the prior art need not be identical to the claimed 
invention but will bar patentability if it is an obvious vari-
ant thereof. In re Foster, 343 F.2d 980, 145 USPQ 166 
(CCPA 1966). See  MPEP ? 706.02 regarding the effective 
U.S. filing date of an application. 

2133.01	Rejections of Continuation-In-Part 
(CIP) Applications 

When applicant files a continuation-in-part whose 
claims are not supported by the parent application, the 
effective filing date is the filing date of the child CIP. Any 
prior art disclosing the invention or an obvious variant 
thereof having a critical reference date more than 1 year 
prior to the filing date of the child will bar the issuance of a 
patent under  35 U.S.C. 102(b).   Paperless Accounting v. 
Bay Area Rapid Transit System, 804 F.2d 659, 665, 231 
USPQ 649, 653 (Fed. Cir. 1986).

2133.02	Rejections Based on Publications 
and Patents 

APPLICANT'S OWN WORK WHICH WAS AVAIL-
ABLE TO THE PUBLIC BEFORE THE GRACE 
PERIOD MAY BE USED IN A 35 U.S.C. 102(b) 
REJECTION

"Any invention described in a printed publication 
more than one year prior to the date of a patent 
application is prior art under Section 102(b), even if the 
printed publication was authored by the patent applicant."   
De Graffenried v. United States, 16 USPQ2d 1321, 1330 
n.7 (Cl. Ct. 1990). "Once an inventor has decided to lift the 
veil of secrecy from his [or her] work, he [or she] must 
choose between the protection of a federal patent, or the 
dedication of his [or her] idea to the public at large." Bonito 
Boats, Inc. v. Thunder Craft Boats, Inc., 489 U.S. 141, 148, 
9 USPQ2d 1847, 1851 (1989).

A 35 U.S.C. 102(b) REJECTION CREATES A STATU-
TORY BAR TO PATENTABILITY OF THE 
REJECTED CLAIMS 

A rejection under 35 U.S.C. 102(b) cannot be overcome 
by affidavits and declarations under 37 CFR 1.131 (Rule 
131 Declarations), foreign priority dates, or evidence that 
applicant himself invented the subject matter. Outside the 
1-year grace period, applicant is barred from obtaining a 
patent containing any anticipated or obvious claims. In re 
Foster, 343 F.2d 980, 984, 145 USPQ 166, 170 (CCPA 
1965).

2133.03	Rejections Based on "Public Use" 
or "On Sale" 

35 U.S.C. 102(b) "contains several distinct bars to pat-
entability, each of which relates to activity or disclosure 
more than one year prior to the date of the application. Two 
of these - the `public use' and the `on sale' objections - are 
sometimes considered together although it is quite clear 
that either may apply when the other does  not." Dart 
Indus. v. E.I. du Pont de Nemours & Co., 489 F.2d 1359, 
1365, 179 USPQ 392, 396 (7th Cir. 1973). There may be a 
public use of an invention absent any sales activity. Like-
wise, there may be a nonpublic, e.g., "secret," sale or offer 
to sell an invention which nevertheless constitutes a statu-
tory bar. Hobbs v. United States, 451 F.2d 849, 859-60, 171 
USPQ 713, 720 (5th Cir. 1971).

In similar fashion, not all "public use" and "on sale" 
activities will necessarily occasion the identical result. 
Although both activities affect how an inventor may use an 
invention prior to the filing of a patent application, "non-
commercial" 35 U.S.C. 102(b) activity may not be viewed 
the same as similar "commercial" activity. See MPEP 
? 2133.03(a) and ? 2133.03(e)(1). Likewise, "public use" 
activity by an applicant may not be considered in the same 
light as similar "public use" activity by one other than an 
applicant. See  MPEP ? 2133.03(a) and  ? 2133.03(e)(7).  
Additionally, the concepts of "completion" and "experi-
mental use" have differing significance in "commercial" 
and "non-commercial" environments. See MPEP 
? 2133.03(c) and  ? 2133.03(e) -  ? 2133.03(e)(6). 

It should be noted that 35 U.S.C. 102(b) may create a bar 
to patentability either alone, if the device in public use or 
placed on sale anticipates a later claimed invention, or in 
conjunction with 35 U.S.C. 103, if the claimed invention 
would have been obvious from the device in conjunction 
with the prior art. LaBounty Mfg. v. United States Int'l 
Trade Comm'n., 958 F.2d 1066, 1071, 22 USPQ2d 1025, 
1028 (Fed. Cir. 1992).

 POLICY CONSIDERATIONS

(A)	"One policy underlying the [on-sale] bar is to 
obtain widespread disclosure of new inventions to the pub-
lic via patents as soon as possible." RCA Corp. v. Data 
Gen. Corp., 887 F.2d 1056, 1062, 12 USPQ2d 1449, 1454 
(Fed. Cir. 1989). 

(B)	The public use and on-sale bars are meant to pre-
vent the inventor from commercially exploiting the exclu-
sivity of his [or her] invention substantially beyond the 
statutorily authorized period. RCA Corp. v. Data Gen. 
Corp., 887 F.2d 1056, 1062, 12 USPQ2d 1449, 1454 (Fed. 
Cir. 1989).  See  MPEP ? 2133.03(e)(1). 

(C)	Another underlying policy for the public use and 
on-sale bars is to discourage "the removal of inventions 
from the public domain which the public justifiably comes 
to believe are freely available." Manville Sales Corp. v. 
Paramount Sys., Inc., 917 F.2d 544, 549, 16 USPQ2d 1587, 
1591 (Fed. Cir. 1990).

2133.03(a)	"Public Use" 

ONE USE IN THE PUBLIC DOMAIN BY ONE PER-
SON MAY BAR A PATENT

"[T]o constitute the public use of an invention it is not 
necessary that more than one of the patent articles should 
be publicly used. The use of a great number may tend to 
strengthen the proof, but one well defined case of such use 
is just as effectual to annul the patent as many." Likewise, it 
is not necessary that more than one person use the inven-
tion. Egbert v. Lippmann, 104 U.S. 333, 336 (1881).

PUBLIC KNOWLEDGE IS NOT NECESSARILY 
PUBLIC USE UNDER 35 U.S.C. 102(b)

Mere knowledge of the invention by the public does not 
warrant rejection under 35 U.S.C. 102(b). 35 U.S.C. 102(b) 
bars public use or sale, not public knowledge. TP Labs., 
Inc., v. Professional Positioners, Inc., 724 F.2d 965, 970, 
220 USPQ 577, 581 (Fed. Cir. 1984).

Note, however, that public knowledge may provide 
grounds for rejection under  35 U.S.C. 102(a). See  MPEP 
? 2132. 

A.	Commercial Versus Noncommercial Use and the 
Impact of Secrecy

1.	"Public Use" and "Non-secret Use" Are Not Nec-
essarily Synonymous

"Public" is not necessarily synonymous with "non- 
secret." The fact "that non-secret uses of the device were 
made [by the inventor or someone connected with the 
inventor] prior to the critical date is not itself dispositive of 
the issue of whether activity barring a patent under 
35 U.S.C. 102(b) occurred. The fact that the device was not 
hidden from view may make the use not secret, but nonse-
cret use is not   ipso facto `public use' activity. Nor, it must 
be added, is all secret use   ipso facto not `public use' 
within the meaning of the statute," if the inventor is making 
commercial use of the invention under circumstances 
which preserve its secrecy. TP Labs., Inc. v. Professional 
Positioners, Inc., 724 F.2d 965, 972, 220 USPQ 577, 583 
(Fed. Cir. 1983) (citations omitted). 

2.	Even If the Invention Is Hidden, Inventor Who 
Puts Machine or Article Embodying the Inven-
tion in Public View Is Barred from Obtaining a 
Patent as the Invention Is in Public Use 

When the inventor or someone connected to the inventor 
puts the invention on display or sells it, there is a "public 
use" within the meaning of 35 U.S.C. 102(b) even though 
by its very nature an invention is completely hidden from 
view as part of a larger machine or article, if the invention 
is otherwise used in its natural and intended way and the 
larger machine or article is accessible to the public.   In re 
Blaisdell, 242 F.2d 779, 783, 113 USPQ 289, 292 (CCPA 
1957); Hall v. Macneale, 107 U.S. 90, 96-97 (1882); Ex 
parte Kuklo, 25 USPQ2d 1387, 1390 (Bd. Pat. App. & 
Inter. 1992) (Display of equipment including the structural 
features of the claimed invention to visitors of laboratory is 
public use even though public did not see inner workings of 
device. The person to whom the invention is publicly dis-
closed need not understand the significance and technical 
complexities of the invention.).

3.	There Is No Public Use If Inventor Restricted Use 
to Locations Where There Was a Reasonable 
Expectation of Privacy and the Use Was for His 
or Her Own Enjoyment 

An inventor's private use of the invention, for his or her 
own enjoyment is not a public use. Moleculon Research 
Corp. v. CBS, Inc., 793 F.2d 1261, 1265, 229 USPQ 805, 
809 (Fed. Cir. 1986) (Inventor showed inventive puzzle to 
close friends while in his dorm room and later the president 
of the company at which he was working saw the puzzle on 
the inventor's desk and they discussed it. Court held that the 
inventor retained control and thus these actions did not 
result in a "public use.").

B.	Use by Third Parties Deriving the Invention from 
Applicant

An Invention Is in Public Use If the Inventor Allows 
Another To Use the Invention Without Restriction or 
Obligation of Secrecy

"Public use" of a claimed invention under 35 U.S.C. 
102(b) occurs when the inventor allows another person to 
use the invention without limitation, restriction or obliga-
tion of secrecy to the inventor."   In re Smith, 714 F.2d 
1127, 1134, 218 USPQ 976, 983 (Fed. Cir. 1983). The pres-
ence or absence of a confidentiality agreement is not itself 
determinative of the public use issue, but is one factor to be 
considered along with the time, place, and circumstances of 
the use which show the amount of control the inventor 
retained over the invention. Moleculon Research Corp. v. 
CBS, Inc., 793 F.2d 1261, 1265, 229 USPQ 805, 809 (Fed. 
Cir. 1986). See Ex parte C, 27 USPQ2d 1492, 1499 (Bd. 
Pat. App. & Inter. 1992) (Inventor sold inventive soybean 
seeds to growers who contracted and were paid to plant the 
seeds to increase stock for later sale. The commercial 
nature of the use of the seed coupled with the "on-sale" 
aspects of the contract and apparent lack of confidentiality 
requirements rose to the level of a "public use" bar.); 
Egbert v. Lippmann, 104 U.S. 333, 336 (1881) (Public use 
found where inventor allowed another to use inventive cor-
set insert, though hidden from view during use, because he 
did not impose an obligation of secrecy or restrictions on its 
use.). 

C.	Use by Independent Third Parties

Use by an Independent Third Party Is Public Use If It 
Sufficiently "Informs" the Public of the Invention or a 
Competitor Could Reasonably Ascertain the Invention

Any "nonsecret" use of an invention by someone uncon-
nected to the inventor, such as someone who has indepen-
dently made the invention, in the ordinary course of a 
business for trade or profit may be a "public use," Bird Pro-
vision Co. v. Owens Country Sausage, Inc., 568 F.2d 369, 
374-76, 197 USPQ 134, 138-40 (5th Cir. 1978). Addition-
ally, even a "secret" use by another inventor of a machine 
or process to make a product is "public" if the details of the 
machine or process are ascertainable by inspection or anal-
ysis of the product that is sold or publicly displayed. Gill-
man v. Stern, 114 F.2d 28, 46 USPQ 430 (2d Cir. 1940); 
Dunlop Holdings, Ltd. v. Ram Golf Corp., 524 F.2d 33, 36-
7, 188 USPQ 481, 483-484 (7th Cir. 1975).  If the details of 
an inventive process are not ascertainable from the product 
sold or displayed and the third party has kept the invention 
as a trade secret then that use is not a public use and will 
not bar a patent issuing to someone unconnected to the 
user. W.L. Gore & Assocs. v. Garlock, Inc., 721 F.2d 1540, 
1550, 220 USPQ 303, 310 (Fed. Cir. 1983). However, a 
device qualifies as prior art if it places the claimed features 
in the public's possession before the critical date even if 
other unclaimed aspects of the device were not publicly 
available. Lockwood v. American Airlines, Inc., 41 
USPQ2d 1961, 1964-65 (Fed. Cir. 1997) (Computer reser-
vation system was prior art even though "essential algo-
rithms of the SABRE software were proprietary and 
confidential and...those aspects of the system that were 
readily apparent to the public would not have been suffi-
cient to enable one skilled in the art to duplicate the 
[unclaimed aspects of the] system." ). The extent that the 
public becomes "informed" of  an invention involved in 
public use activity by one other than an applicant depends 
upon the factual circumstances surrounding the activity and 
how these comport with the policies underlying the on sale 
and public use bars. Manville Sales Corp. v. Paramount 
Sys., Inc., 917 F.2d 544, 549, 16 USPQ2d 1587, 1591 (Fed. 
Cir. 1990) (quoting King Instrument Corp. v. Otari Corp., 
767 F.2d 833, 860, 226 USPQ 402, 406 (Fed Cir. 1985)). 
By way of example, in an allegedly "secret" use by a third 
party other than an applicant, if a large number of employ-
ees of such a party, who are not under a promise of secrecy, 
are permitted unimpeded access to an invention, with affir-
mative steps by the party to educate other employees as to 
the nature of the invention, the public is "informed." 
Chemithon Corp. v. Proctor & Gamble Co., 287 F. Supp. 
291, 308, 159 USPQ 139, 154 (D.Md. 1968), aff'd., 427 
F.2d 893, 165 USPQ 678 (4th Cir. 1970).

Even if public use activity by one other than an applicant 
is not sufficiently "informing," there may be adequate 
grounds upon which to base a rejection under 35 U.S.C. 
102(f) and  35 U.S.C. 102(g). See   Dunlop Holdings Ltd. v. 
Ram Golf Corp., 524 F.2d 33, 188 USPQ 481 (7th Cir. 
1975). See  MPEP ? 2137 and  ? 2138. 

2133.03(b)	"On Sale"  [R-1]

An impermissible sale has occurred if there was a defi-
nite sale, or offer to sell, more than 1 year before the effec-
tive filing date of the U.S. application and the subject 
matter of the sale, or offer to sell, fully anticipated the 
claimed invention or would have rendered the claimed 
invention obvious by its addition to the prior art. Ferag AG 
v. Quipp, Inc., 45 F.3d 1562, 1565, 33 USPQ2d 1512, 1514 
(Fed. Cir. 1995). 

I.	THE MEANING OF "SALE"

A sale is a contract between parties wherein the seller 
agrees "to give and to pass rights of property" in return for 
the buyer's payment or promise "to pay the seller for the 
things bought or sold." In re Caveney, 761 F.2d 671, 676, 
226 USPQ 1, 4 (Fed. Cir. 1985).

A.	Conditional Sale May Bar a Patent

An invention may be deemed to be "on sale" even 
though the sale was conditional. The fact that the sale is 
conditioned on buyer satisfaction does not, without more, 
prove that the sale was for an experimental purpose. Strong 
v. General Elec. Co., 434 F.2d 1042, 1046, 168 USPQ 8, 12 
(5th Cir. 1970).

B.	Nonprofit Sale May Bar a Patent

A "sale" need not be for profit to bar a patent. If the sale 
was for the commercial exploitation of the invention, it is 
"on sale" within the meaning of  35 U.S.C. 102(b). In re 
Dybel, 524 F.2d 1393, 1401, 187 USPQ 593, 599 (CCPA 
1975) ("Although selling the devices for a profit would 
have demonstrated the purpose of commercial exploitation, 
the fact that appellant realized no profit from the sales does 
not demonstrate the contrary.").

C.	A Single Sale or Offer To Sell May Bar a Patent

Even a single sale or offer to sell the invention may bar 
patentability under  35 U.S.C. 102(b). Consolidated Fruit-
Jar Co. v. Wright, 94 U.S. 92, 94 (1876); Atlantic Thermo-
plastics Co. v. Faytex Corp., 970 F.2d 834, 836-37, 23 
USPQ2d 1481, 1483 (Fed. Cir. 1992).

D.	A Sale of Rights Is Not a Sale of the Invention and 
Will Not in Itself Bar a Patent

"An assignment or sale of the rights, such as patent 
rights, in the invention is not a sale of `the invention' 
within the meaning of section 102(b)." The sale must 
involve the delivery of the physical invention itself. 
Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 
1265, 229 USPQ 805, 809 (Fed. Cir. 1986).

E.	Buyer Must Be Uncontrolled by the Seller or  
Offerer

A sale or offer for sale must take place between separate 
entities. In re Caveney, 761 F.2d 671, 676, 226 USPQ 1, 4 
(Fed. Cir. 1985). "Where the parties to the alleged sale are 
related, whether there is a statutory bar depends on whether 
the seller so controls the purchaser that the invention 
remains out of the public's hands. Ferag AG v. Quipp, Inc., 
45 F.3d 1562, 1566, 33 USPQ2d 1512, 1515 (Fed. Cir. 
1995) (Where the seller is a parent company of the buyer 
company, but the President of the buyer company had 
"essentially unfettered" management authority over the 
operations of the buyer company, the sale was a statutory 
bar.).

II.	OFFERS FOR SALE

A.	Rejected or Unreceived Offer for Sale Is Enough 
To Bar a Patent

Since the statute creates a bar when an invention is 
placed "on sale," a mere offer to sell is sufficient commer-
cial activity to bar a patent. In re Theis, 610 F.2d 786, 791, 
204 USPQ 188, 192 (CCPA 1979). Even a rejected offer 
may create an on sale bar. UMC Elecs. v. United States, 816 
F.2d 647, 653, 2 USPQ2d 1465, 1469 (Fed. Cir. 1987). In 
fact, the offer need not even be actually received by a pro-
spective purchaser. Wende v. Horine, 225 F. 501 (7th Cir. 
1915). 

B.	Delivery of the Offered Item Is Not Required

"It is not necessary that a sale be consummated for the 
bar to operate." Buildex v. Kason Indus., Inc., 849 F.2d 
1461, 1463-64, 7 USPQ2d 1325, 1327-28 (Fed. Cir. 1988) 
(citations omitted).  >See also Weatherchem Corp. v. J.L. 
Clark Inc., 163 F.3d 1326, 1333, 49 USPQ2d 1001, 1006-
07 (Fed. Cir. 1998)(A signed purchase agreement prior to 
the critical date constituted a commercial offer; it was 
immaterial that there was no delivery of later patented caps 
and no exchange of money until after critical date.).<

C.	Seller Need Not Have the Goods "On Hand" when 
the Offer for Sale Is Made

Goods need not be "on hand" and transferred at the time 
of the sale or offer. The date of the offer for sale is the 
effective date of the "on sale" activity. J. A. La Porte, Inc. v. 
Norfolk Dredging Co., 787 F.2d 1577, 1582, 229 USPQ 
435, 438 (Fed. Cir. 1986). However, the invention must be 
** >complete and "ready for patenting" (see MPEP 
? 2133.03(c)) before the critical date. Pfaff v. Wells Elecs., 
Inc. , 525 U.S. 55, 67, 119 S.Ct. 304, 311-12, 48 USPQ2d 
1641, 1647 (1998).<  See also Micro Chemical, Inc. v. 
Great Plains Chemical Co., 103 F.3d 1538, 1545, 41 
USPQ2d 1238, 1243 (Fed. Cir. 1997) (The on-sale bar was 
not triggered by an offer to sell because the inventor "was 
not close to completion of the invention at the time of the 
alleged offer and had not demonstrated a high likelihood 
that the invention would work for its intended purpose 
upon completion."); Shatterproof Glass Corp. v. Libbey-
Owens Ford Co., 758 F.2d 613, 225 USPQ 634 (Fed. Cir. 
1985) (Where there was no evidence that the samples 
shown to the potential customers were made by the new 
process and apparatus, the offer to sell did not rise to the 
level of an on sale bar.). Compare Barmag Barmer 
Maschinenfabrik AG v. Murata Mach., Ltd., 731 F.2d 831, 
221 USPQ 561 (Fed. Cir. 1984) (Where a "make shift" 
model of the inventive product was shown to the potential 
purchasers in conjunction with the offer to sell, the offer 
was enough to bar a patent under 35 U.S.C. 102(b).). 

III.	SALE BY INVENTOR, ASSIGNEE OR 
OTHERS ASSOCIATED WITH THE  
INVENTOR IN THE COURSE OF BUSINESS

A.	Sale Activity Need Not Be Public

Unlike questions of public use, there is no requirement 
that "on sale" activity be "public." "Public" as used in 
35 U.S.C. 102(b) modifies "use" only. "Public" does not 
modify "sale." Hobbs v. United States, 451 F.2d 849, 171 
USPQ 713, 720 (5th Cir. 1971). 

B.	Inventor's Consent to the Sale Is Not a Prerequisite 
To Finding an On Sale Bar

If the invention was placed on sale by a third party who 
obtained the invention from the inventor, a patent is barred 
even if the inventor did not consent to the sale or have 
knowledge that the invention was embodied in the sold arti-
cle. Electric Storage Battery Co. v. Shimadzu, 307 U.S. 5, 
41 USPQ 155 (1938); In re Blaisdell, 242 F.2d 779, 783, 
113 USPQ 289, 292 (CCPA 1957); CTS Corp. v. Electro 
Materials Corp. of America, 469 F. Supp. 801, 819, 202 
USPQ 22, 38 (S.D.N.Y. 1979). 

C.	Objective Evidence of Intent To Sell Is Needed

In determining if a sale or offer to sell has occurred a key 
question to ask is whether, under the totality of the circum-
stances, the inventor placed his or her invention on sale, 
objectively manifested by a sale or offer for sale of a prod-
uct that embodies the invention claimed in the application. 
Objective evidence such as a description of the inventive 
product in the contract of sale or in another communication 
with the purchaser controls over an uncommunicated intent 
by the seller to deliver the inventive product under the con-
tract for sale. Ferag AG v. Quipp, Inc., 45 F.3d 1562, 1567, 
33 USPQ2d 1512, 1516 (Fed. Cir. 1995) (On sale bar found 
where initial negotiations and agreement containing con-
tract for sale neither clearly specified nor precluded use of 
the inventive design but an order confirmation more than 1 
year prior to filing of patent application for the inventive 
design did specify use of inventive design.). The purchaser 
need not have actual knowledge of the invention for it to be 
on sale. "For example, merely offering to sell a product by 
way of an advertisement or invoice may be evidence of a 
definite offer for sale or a sale of a claimed invention even 
though no details are disclosed. That the offered product is 
in fact the claimed invention may be established by any rel-
evant evidence, such as memoranda, drawings, correspon-
dence, and testimony of witnesses." RCA Corp. v. Data 
Gen. Corp., 887 F.2d 1056, 1060, 12 USPQ2d 1449, 1452 
(Fed. Cir. 1989). However, "what the purchaser reasonably 
believes the inventor to be offering is relevant to whether, 
on balance, the offer objectively may be said to be of the 
patented invention." Envirotech Corp. v. Westech Eng'g, 
Inc., 904 F.2d 1571, 1576, 15 USPQ2d 1230, 1234 (Fed. 
Cir. 1990) (Where a proposal to supply a general contractor 
with a product did not mention a new design but, rather, 
referenced a prior art design, the uncommunicated intent of 
the supplier to supply the new design if awarded the con-
tract did not constitute an "on sale" bar to a patent on the 
new design, even though the supplier's bid reflected the 
lower cost of the new design.). 

IV.	SALES BY INDEPENDENT THIRD PARTIES

A.	Sales or Offers for Sale by Independent Third  
Parties Will Bar a Patent

Sale or offer for sale of the invention by an independent 
third party more than 1 year before the filing date of appli-
cant's patent will bar applicant from obtaining a patent. 
"An exception to this rule exists where a patented method 
is kept secret and remains secret after a sale of the unpat-
ented product of the method. Such a sale prior to the critical 
date is a bar if engaged in by the patentee or patent appli-
cant, but not if engaged in by another."   In re Caveney, 761 
F.2d 671, 675-76, 226 USPQ 1, 3-4 (Fed. Cir. 1985).

B.	Nonprior Art Publications Can Be Used as 
Evidence of Sale Before the Critical Date

Abstracts identifying a product's vendor containing 
information useful to potential buyers such as whom to 
contact, price terms, documentation, warranties, training 
and maintenance along with the date of product release or 
installation before the inventor's critical date may provide 
sufficient evidence of prior sale by a third party to support a 
rejection based on 35 U.S.C. 102(b) or 103. In re Epstein, 
32 F.3d 1559, 31 USPQ2d 1817 (Fed. Cir. 1994) (Exam-
iner's rejection was based on nonprior art published 
abstracts which disclosed software products meeting the 
claims. The abstracts specified software release dates and 
dates of first installation which were more than 1 year 
before applicant's filing date.).

2133.03(c)	The "Invention"  [R-1]

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

(b)	the invention was?in public use or on sale in this country, more 
than one year prior to the date of the application for patent in the United 
States

*****

(Emphasis added).

I.	LEVEL OF COMPLETENESS REQUIRED

The level of completion required likely will differ in 
cases of "public use" which are not intertwined with a sale. 
UMC Elecs. Co. v. United States, 816 F.2d 647, 652 n.6, 2 
USPQ2d 1465, 1468 n.6 (Fed. Cir. 1987). The court deci-
sions do not address the level required in pure "public use" 
cases but it is unlikely that the invention can be publicly 
used without a working embodiment. The case law pre-
sented below is directed to "on sale" situations.

*The Invention **>Must Be "Ready for Patenting"< at 
the Time of the Sale

>In Pfaff v. Wells Elecs., Inc., 119 S.Ct. 304, 311-12, 48 
USPQ2d 1641, 1647 (1998), the Supreme Court enunciated 
a two-prong test for determining whether an invention was 
"on sale" within the meaning of 35 U.S.C. 102(b) even if it 
has not yet been reduced to practice. "[T]he on-sale bar 
applies when two conditions are satisfied before the critical 
date [more than one year before the effective filing date of 
the U.S. application]. First, the product must be the subject 
of a commercial offer for sale?. Second, the invention 
must be ready for patenting." Pfaff, 119 S.Ct. at 311-12, 48 
USPQ2d at 1646-47. "Ready for patenting," the second 
prong of the Pfaff test, "may be satisfied in at least two 
ways: by proof of reduction to practice before the critical 
date; or by proof that prior to the critical date the inventor 
had prepared drawings or other descriptions of the inven-
tion that were sufficiently specific to enable a person 
skilled in the art to practice the invention." Pfaff, 199 S.Ct. 
at 311-12, 48 USPQ2d at 1647 (The patent was held invalid 
because the invention for a computer chip socket was 
"ready for patenting" when it was offered for sale more 
than one year prior to the application filing date. Even 
though the invention had not yet been reduced to practice, 
the manufacturer was able to produce the claimed computer 
chip sockets using the inventor's detailed drawings and 
specifications, and those sockets contained all elements of 
invention claimed in the patent.). See also Weatherchem 
Corp. v. J.L. Clark Inc., 163 F.3d 1326, 1333, 49 USPQ2d 
1001, 1006-07 (Fed. Cir. 1998)(The invention was held 
"ready for patenting" since the detailed drawings of plastic 
dispensing caps offered for sale "contained each limitation 
of the claims and were sufficiently specific to enable per-
son skilled in art to practice the invention".).<  

If the invention was actually reduced to practice before 
being sold or offered for sale more than 1 year before filing 
of the application, a patent will be barred. In re Hamilton, 
882 F.2d 1576, 1580, 11 USPQ2d 1890, 1893 (Fed. Cir. 
1989).   >"If a product that is offered for sale inherently 
possesses each of the limitations of the claims, then the 
invention is on sale, whether or not the parties to the trans-
action recognize that the product possesses the claimed 
characteristics." Abbott Laboratories v. Geneva Pharma-
ceuticals, Inc., 182 F.3d 1315, 1319, 51 USPQ2d 1307, 
1310 (Fed. Cir. 1999) (Claim for a particular anhydrous 
crystalline form of a pharmaceutical compound was held 
invalid under the on-sale bar of 35 U.S.C. 102(b), even 
though the parties to the U.S. sales of the foreign manufac-
tured compound did not know the identity of the particular 
crystalline form.)<  Actual reduction to practice in *>the< 
context >of an on-sale bar issue< usually requires testing 
under actual working conditions in such a way as to dem-
onstrate the practical utility of an invention for its intended 
purpose beyond the probability of failure, unless by virtue 
of the very simplicity of an invention its practical opera-
tiveness is clear. Field v. Knowles, 183 F.2d 593, 601, 86 
USPQ 373, 379 (CCPA 1950); Steinberg v. Seitz, 517 F.2d 
1359, 1363, 186 USPQ 209, 212 (CCPA 1975). 

**

The invention need not be ready for satisfactory com-
mercial marketing for sale to bar a patent. Atlantic Thermo-
plastics Co. v. Faytex Corp., 970 F.2d 834, 836-37, 23 
USPQ2d 1481, 1483 (Fed. Cir. 1992). 

II.	INVENTOR HAS SUBMITTED A 37 CFR 1.131 
AFFIDAVIT OR DECLARATION

Affidavits or declarations submitted under 37 CFR 1.131 
to swear behind a reference  may constitute, among other 
things, an admission that an invention was "complete" 
more than 1 year before the filing of an application. See   In 
re Foster, 342 F.2d 980, 987-88, 145 USPQ 166, 173 
(CCPA 1965); Dart Indus. v. E.I. duPont de Nemours & 
Co., 489 F.2d 1359, 1365, 179 USPQ 392, 396 (7th Cir. 
1973). Also see  MPEP ? 715.10. 

2133.03(d)	"In This Country" 

For purposes of judging the applicability of the 
35 U.S.C. 102(b) bars, public use or on sale activity must 
take place in the United States. The "on sale" bar does not 
generally apply where both manufacture and delivery occur 
in a foreign country. Gandy v. Main Belting Co., 143 U.S. 
587, 593 (1892). However, "on sale" status can be found if 
substantial activity prefatory to a "sale" occurs in the 
United States. Robbins Co. v. Lawrence Mfg. Co., 482 F.2d 
426, 433, 178 USPQ 577, 583 (9th Cir. 1973). An offer for 
sale, made or originating in this country, may be sufficient 
prefatory activity to bring the offer within the terms of the 
statute, even though sale and delivery take place in a for-
eign country. The same rationale applies to an offer by a 
foreign manufacturer which is communicated to a prospec-
tive purchaser in the United States prior to the critical date. 
CTS Corp. v. Piher Int'l Corp., 593 F.2d 777, 201 USPQ 
649 (7th Cir. 1979).

2133.03(e)	Permitted Activity; Experimental 
Use

The basic test is that experimentation must be the pri-
mary purpose and any commercial exploitation must be 
incidental.

If the use or sale was experimental, there is no bar  under  
35 U.S.C. 102(b). "A use or sale is experimental for pur-
poses of section 102(b) if it represents a bona fide effort to 
perfect the invention or to ascertain whether it will answer 
its intended purpose.?If any commercial exploitation does 
occur, it must be merely incidental to the primary purpose 
of the experimentation to perfect the invention." LaBounty 
Mfg. v. United States Int'l Trade Comm'n, 958 F.2d 1066, 
1071, 22 USPQ2d 1025, 1028 (Fed. Cir. 1992) (quoting 
Pennwalt Corp. v. Akzona Inc., 740 F.2d 1573, 1581, 222 
USPQ 833, 838 (Fed. Cir. 1984)). "The experimental use 
exception?does not include market testing where the 
inventor is attempting to gauge consumer demand for his 
claimed invention. The purpose of such activities is com-
mercial exploitation and not experimentation." In re Smith, 
714 F.2d 1127, 1134, 218 USPQ 976, 983 (Fed. Cir. 1983).

2133.03(e)(1)	Commercial Exploitation 

THERE MUST BE NO ATTEMPT AT MARKET 
PENETRATION BEFORE THE CRITICAL DATE

A strong policy of the on sale and public use bars is the 
prevention of inventors from exploiting their inventions 
commercially more than 1 year prior to the filing of a 
patent application. Therefore, if applicant's precritical date 
activity is, at any level, an attempt at market penetration, a 
patent is barred. Thus, even if there is bona fide experimen-
tal activity, an inventor may not commercially exploit an 
invention more than 1 year prior to the filing date of an 
application. In re Theis, 610 F.2d 786, 793, 204 USPQ 188, 
194 (CCPA 1979).

THE COMMERCIAL ACTIVITY MUST LEGITI-
MATELY ADVANCE DEVELOPMENT OF THE 
INVENTION TOWARDS COMPLETION

As the degree of commercial exploitation surrounding  
35 U.S.C. 102(b) activity increases, the burden on an appli-
cant to establish clear and convincing evidence of experi-
mental activity with respect to a public use becomes more 
difficult. Where the examiner has found a prima facie case 
of a sale or an offer to sell, this burden will rarely be met 
unless clear and convincing necessity for the experimenta-
tion is established by the applicant. This does not mean, of 
course, that there are no circumstances which would permit 
alleged experimental activity in an atmosphere of commer-
cial exploitation. In certain circumstances, even a sale may 
be necessary to legitimately advance the experimental 
development of an invention if the primary purpose of the 
sale is experimental. In re Theis, 610 F.2d 786, 793, 204 
USPQ 188, 194 (CCPA 1979); Robbins Co. v. Lawrence 
Mfg. Co., 482 F.2d 426, 433, 178 USPQ 577, 582 (9th Cir. 
1973). However, careful scrutiny by the examiner of the 
objective factual circumstances surrounding such a sale is 
essential. See Ushakoff v. United States, 327 F.2d 669, 140 
USPQ 341 (Ct.Cl. 1964); Cloud v. Standard Packaging 
Corp., 376 F.2d 384,  153 USPQ 317 (7th Cir. 1967). 

SIGNIFICANT FACTORS INDICATIVE OF "COM-
MERCIAL EXPLOITATION"

As discussed in  MPEP ? 2133.03, a policy consideration 
in questions of 35 U.S.C. 102(b) activity is premature 
"commercial exploitation" of a "completed" or nearly com-
pleted invention (see MPEP ? 2133.03(c)). The extent of 
commercial activity which constitutes 35 U.S.C. 102(b) 
"on sale" status depends upon the circumstances of the 
activity, the basic indicator being the subjective intent of 
the inventor as manifested through objective evidence. The 
following activities should be used by the examiner as indi-
cia of this subjective intent:

(A)	Preparation of various contemporaneous "com-
mercial" documents, e.g., orders, invoices, receipts, deliv-
ery schedules, etc.; 

(B)	Preparation of price lists (Akron Brass Co. v. 
Elkhart Brass Mfg. Co., 353 F.2d 704, 709, 147 USPQ 301, 
305 (7th Cir. 1965) and distribution of price quotations 
(Amphenol Corp. v. General. Time Corp., 158 USPQ 113, 
117 (7th Cir. 1968)); 

(C)	Display of samples to prospective customers (Cat-
aphote Corp. v. DeSoto Chemical Coatings, Inc., 356 F.2d 
24, 27, 148 USPQ 527, 529 (9th Cir. 1966) mod. on other 
grounds, 358 F.2d 732, 149 USPQ 159 (9th Cir.), cert. 
denied, 385 U.S. 832 (1966); Chicopee Mfg. Corp. v. 
Columbus Fiber Mills Co., 165 F.Supp. 307, 323-325, 118 
USPQ 53, 65-67 (M.D.Ga. 1958));

(D)	Demonstration of models or prototypes (General 
Elec. Co. v. United States, 206 USPQ 260, 266-67 (Ct. Cl. 
1979); Red Cross Mfg. v. Toro Sales Co., 525 F.2d 1135, 
1140, 188 USPQ 241, 244-45 (7th Cir. 1975); Philco Corp. 
v. Admiral Corp., 199 F. Supp. 797, 815-16, 131 USPQ 
413, 429-30 (D.Del. 1961)), especially at trade conventions 
(InterRoyal Corp. v. Simmons Co., 204 USPQ 562, 563-65 
(S.D. N.Y. 1979)), and even though no orders are actually 
obtained (Monogram Mfg. v. F. & H. Mfg.,144 F.2d 412, 62 
USPQ 409, 412 (9th Cir. 1944)); 

(E)	Use of an invention where an admission fee is 
charged (In re Josserand, 188 F.2d 486, 491, 89 USPQ 371, 
376 (CCPA 1951); Greenewalt v. Stanley, 54 F.2d 195, 12 
USPQ 122 (3d Cir. 1931)); and 

(F)	Advertising in publicity releases, brochures, and 
various periodicals (In re Theis, 610 F.2d 786, 792 n.6, 204 
USPQ 188, 193 n. 6 (CCPA 1979); InterRoyal Corp. v. 
Simmons Co., 204 USPQ 562, 564-66 (S.D.N.Y.1979); 
Akron Brass, Inc.  v. Elkhart Brass Mfg., Inc., 353 F.2d 704, 
709, 147 USPQ 301, 305 (7th Cir.1965); Tucker Aluminum 
Prods. v. Grossman, 312 F.2d 393, 394, 136 USPQ 244, 
245 (9th Cir. 1963)). 

The above activities may be determinative of "commer-
cial exploitation" even though:

(A)	Prices are estimated rather than established, 

(B)	No commercial production runs have been made, 
and 

(C)	The invention is never actually sold. Chromalloy 
Am. Corp. v. Alloy Surfaces Co., 339 F. Supp. 859, 869, 173 
USPQ 295, 301-02 (D.Del. 1972).

2133.03(e)(2)	Intent 

"When sales are made in an ordinary commercial envi-
ronment and the goods are placed outside the inventor's 
control, an inventor's secretly held subjective intent to 
`experiment,' even if true, is unavailing without objective 
evidence to support the contention. Under such circum-
stances, the customer at a minimum must be made aware of 
the experimentation." LaBounty Mfg., Inc. v. United States 
Int'l  Trade Comm'n, 958 F.2d 1066, 1072, 22 USPQ2d 
1025, 1029 (Fed. Cir. 1992) (quoting   Harrington Mfg. Co. 
v. Powell Mfg. Co., 815 F.2d 1478, 1480 n.3, 2 USPQ2d 
1364, 1366 n.3 (Fed. Cir. 1986); Paragon Podiatry Labora-
tory, Inc. v. KLM Labs., Inc., 984 F.2d 1182, 25 USPQ2d 
1561 (Fed. Cir. 1993) (Paragon sold the inventive units to 
the trade as completed devices without any disclosure to 
either doctors or patients of their involvement in alleged 
testing. Evidence of the inventor's secretly held belief that 
the units were not durable and may not be satisfactory for 
consumers was not sufficient, alone, to avoid a statutory 
bar.). 

2133.03(e)(3)	"Completeness" of the Invention 

EXPERIMENTAL USE ENDS WHEN THE INVEN-
TION IS ACTUALLY REDUCED TO PRACTICE

Experimental use "means perfecting or completing an 
invention to the point of determining that it will work for its 
intended purpose." Therefore, experimental use "ends with 
an actual reduction to practice." RCA Corp. v. Data Gen. 
Corp., 887 F.2d 1056, 1061, 12 USPQ2d 1449, 1453 (Fed. 
Cir. 1989). If the examiner concludes from the evidence of 
record that an applicant was satisfied that an invention was 
in fact "complete," awaiting approval by the applicant from 
an organization such as Underwriters' Laboratories will not 
normally overcome this conclusion.   InterRoyal Corp. v. 
Simmons Co., 204 USPQ 562, 566 (S.D.N.Y. 1979); Skil 
Corp. v. Rockwell Manufacturing Co., 358 F. Supp. 1257, 
1261, 178 USPQ 562, 565 (N.D.Ill. 1973), aff'd. in part, 
rev'd in part sub nom. Skil Corp. v. Lucerne Products Inc., 
503 F.2d 745, 183 USPQ 396, 399 (7th Cir. 1974), cert. 
denied, 420 U.S. 974, 185 USPQ 65 (1975). See MPEP 
? 2133.03(c) for more information of what constitutes a 
"complete" invention.

The fact that alleged experimental activity does not lead 
to specific modifications or refinements of an invention is 
evidence, although not conclusive evidence, that such 
activity is not within the realm permitted by the statute. 
This is especially the case where the evidence of record 
clearly demonstrates to the examiner that an invention was 
considered "complete" by an inventor at the time of the 
activity. Nevertheless, any modifications or refinements 
which did result from such experimental activity must at 
least be a feature of the claimed invention to be of any pro-
bative value. In re Theis, 610 F.2d 786, 793, 204 USPQ 
188, 194 (CCPA 1979).

DISPOSAL OF PROTOTYPES

Where a prototype of an invention has been disposed of 
by an inventor before the critical date, inquiry by the exam-
iner should focus upon the intent of the inventor and the 
reasonableness of the disposal under all circumstances. The 
fact that an otherwise reasonable disposal of a prototype 
involves incidental income is not necessarily fatal. In re 
Dybel, 524 F.2d 1393, 1399, n.5, 187 USPQ 593, 597 
n.5 (CCPA 1975). However, if a prototype is considered 
"complete" by an inventor and all experimentation on the 
underlying invention has ceased, unrestricted disposal of 
the prototype constitutes a bar under  35 U.S.C. 102(b). In 
re Blaisdell, 242 F.2d 779, 113 USPQ 289 (CCPA 1957);   
contra, Watson v. Allen, 254 F.2d 342, 117 USPQ 68 (D.C. 
Cir. 1958).

2133.03(e)(4)	Factors Indicative of an  
Experimental Purpose 

The Court in   City of Elizabeth v. American Nicholson 
Pavement Co., 97 U.S. 126 (1878) found several factors 
persuasive of experimental activity:

Supreme Court decisions subsequent to City of Elizabeth 
identify other significant factors which may be determina-
tive of experimental purpose:

(A)	the nature of the invention was such that any test-
ing had to be to some extent public;

(B)	testing had to be for a substantial period of time;

(C)	testing was conducted under the supervision and 
control of the inventor; and

(D)	the inventor regularly inspected the invention dur-
ing the period of experimentation. 

(E)	extent of any obligations or limitation placed on a 
user during a period of experimental activity, as well as the 
extent of an testing actually performed during such period 
(Egbert v. Lippmann, 104 U.S. 333 (1881));

(F)	conditional nature of any sale associated with 
experimental activity (Hall v. Macneale, 107 U.S. 90 
(1882)); and

(G)	length of time and number of cases in which 
experimental activity took place, viewed in light of what 
was reasonably necessary for an alleged experimental pur-
pose (International Tooth Crown Co. v. Gaylord, 140 U.S. 
55 (1891)). 

Other judicial opinions have supplemented these factors 
by looking to the extent of any:

(H)	explicit or implicit obligations placed upon a user 
to supply an inventor with the results of any testing con-
ducted during an experimental period and the extent of 
inquiry made by the inventor regarding the testing (Robbins 
Co. v. Lawrence Mfg. Co., 178 USPQ 577, 583 (9th Cir. 
1973));

(I)	disclosure by an inventor to a user regarding what 
the inventor considers as unsatisfactory operation of the 
invention (In re Dybel, 524 F.2d 1393, 1401, 187 USPQ 
593, 599 (CCPA 1975)); 

(J)	effort on the part of an inventor to retrieve any 
experimental samples at the end of an experimental period 
(Omark Indus. v. Carlton Co., 458 F.Supp. 449, 454, 201 
USPQ 825, 830 (D.Ore. 1978)); and

(K)	a doctor-patient relationship where the inventor/
doctor conducted the experimentation (TP Labs. Inc. v. 
Professional Positioners, Inc., 724 F.2d 965, 971, 220 
USPQ 577, 582 (Fed. Cir. 1984).

Summarizing the above, once alleged experimental 
activity is advanced by an applicant to explain a prima 
facie case under 35 U.S.C. 102(b), the examiner must 
determine whether the scope and length of the activity were 
reasonable in terms of the experimental purpose intended 
by the applicant and the nature of the subject matter 
involved. No one of, or particular combination of, factors 
(A) through (K) is necessarily determinative of this pur-
pose.

2133.03(e)(5)	Experimentation and Degree of 
Supervision and Control 

THE INVENTOR MUST MAINTAIN SUFFICIENT 
CONTROL OVER THE INVENTION DURING 
TESTING BY THIRD PARTIES

As discussed with reference to City of Elizabeth v. Amer-
ican Nicholson Pavement Co., 97 U.S. 126 (1878), a signif-
icant determinative factor in questions of experimental 
purpose is the extent of supervision and control maintained 
by an inventor over an invention during an alleged period 
of experimentation. Once a period of experimental activity 
has ended and supervision and control has been relin-
quished by an inventor without any restraints on subse-
quent use of an invention, an unrestricted subsequent use of 
the invention is a 35 U.S.C. 102(b) bar. In re Blaisdell, 242 
F.2d 779, 784, 113 USPQ 289, 293 (CCPA 1957). 

2133.03(e)(6)	Permitted Experimental  
Activity and Testing 

DEVELOPMENTAL TESTING IS PERMITTED

Testing of an invention in the normal context of its tech-
nological development is generally within the realm of per-
mitted experimental activity. Likewise, experimentation to 
determine utility, as that term is applied in 35 U.S.C. 101, 
may also constitute permissible activity. See General 
Motors Corp. v. Bendix Aviation Corp., 123 F. Supp. 506, 
521, 102 USPQ 58, 69 (N.D.Ind. 1954). For example, 
where an invention relates to a chemical composition with 
no known utility, i.e., a patent application for the composi-
tion could not be filed (35 U.S.C. 101; 35 U.S.C. 112, first 
paragraph), continued testing to find utility would likely be 
permissible under 35 U.S.C. 102(b), absent a sale of the 
composition or other evidence of commercial exploitation. 

MARKET TESTING IS NOT PERMITTED

Experimentation to determine product acceptance, i.e., 
market testing, is typical of a trader's and not an inventor's 
experiment and is thus not within the area of permitted 
experimental activity. Smith & Davis Mfg. Co. v. Mellon, 
58 F. 705, 707 (8th Cir. 1893) Likewise, testing of an 
invention for the benefit of appeasing a customer, or to con-
duct "minor `tune up' procedures not requiring an inven-
tor's skills, but rather the skills of a competent technician," 
are also not within the exception. In re Theis, 610 F.2d 786, 
793, 204 USPQ 188, 193-94 (CCPA 1979).

EXPERIMENTAL ACTIVITY IN THE CONTEXT 
OF DESIGN APPLICATIONS

The public use of an ornamental design which is directed 
toward generating consumer interest in the aesthetics of the 
design is not an experimental use. In re Mann, 861 F.2d 
1581, 8 USPQ2d 2030 (Fed. Cir. 1988) (display of a 
wrought iron table at a trade show held to be public use). 
However, "experimentation directed to functional features 
of a product also containing an ornamental design may 
negate what otherwise would be considered a public use 
within the meaning of section 102(b)." Tone Brothers, Inc. 
v. Sysco Corp., 28 F.3d 1192, 1196,  31 USPQ2d 1321, 
1326 (Fed. Cir. 1994) (A study wherein students evaluated 
the effect of the functional features of a spice container 
design may be considered an experimental use.).

2133.03(e)(7)	Activity of an Independent 
Third Party Inventor 

EXPERIMENTAL USE EXCEPTION IS PERSONAL 
TO AN APPLICANT

The statutory bars of 35 U.S.C. 102(b) are applicable 
even though public use or on sale activity is by a party 
other than an applicant. Where an applicant presents evi-
dence of experimental activity by such other party, the evi-
dence will not overcome the prima facie case under 
35 U.S.C. 102(b) based upon the activity of such party 
unless the activity was under the supervision and control of 
the applicant. Magnetics v. Arnold Eng'g Co., 438 F.2d 72, 
74, 168 USPQ 392, 394 (7th Cir. 1971), Bourne v. Jones, 
114 F.Supp. 413, 419, 98 USPQ 206, 210 (S.D. Fla. 1951), 
aff'd., 207 F.2d 173, 98 USPQ 205 (5th Cir. 1953), cert. 
denied, 346 U.S. 897, 99 USPQ 490 (1953); contra, Watson 
v. Allen, 254 F.2d 342, 117 USPQ 68 (D.C.Cir. 1957). In 
other words, the experimental use activity exception is per-
sonal to an applicant.

2134	35 U.S.C. 102(c) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

(c)	he has abandoned the invention.

*****

UNDER 35 U.S.C. 102(c), AN ABANDONMENT 
MUST BE INTENTIONAL

"Actual abandonment under 35 U.S.C. 102(c) requires 
that the inventor intend to abandon the invention, and intent 
can be implied from the inventor's conduct with respect to 
the invention. In re Gibbs, 437 F.2d 486, 168 USPQ 578 
(CCPA 1971). Such intent to abandon the invention will not 
be imputed, and every reasonable doubt should be resolved 
in favor of the inventor." Ex parte Dunne, 20 USPQ2d 
1479 (Bd. Pat. App. & Inter. 1991).

DELAY IN MAKING FIRST APPLICATION

Abandonment under 35 U.S.C. 102(c) requires a deliber-
ate, though not necessarily express, surrender of any rights 
to a patent. To abandon the invention the inventor must 
intend a dedication to the public. Such dedication may be 
either express or implied, by actions or inactions of the 
inventor. Delay alone is not sufficient to infer the requisite 
intent to abandon. Moore v. United States, 194 USPQ 423, 
428 (Ct. Cl. 1977) (The drafting and retention in his own 
files of two patent applications by inventor indicates an 
intent to retain his invention; delay in filing the applications 
was not sufficient to establish abandonment); but see Davis 
Harvester Co., Inc. v. Long Mfg. Co., 252 F. Supp. 989, 
1009-10, 149 USPQ 420, 435-436 (E.D. N.C. 1966) 
(Where the inventor does nothing over a period of time to 
develop or patent his invention, ridicules the attempts of 
another to develop that invention and begins to show active 
interest in promoting and developing his invention only 
after successful marketing by another of a device embody-
ing that invention, the inventor has abandoned his invention 
under  35 U.S.C. 102(c).).

DELAY IN REAPPLYING FOR PATENT AFTER 
ABANDONMENT OF PREVIOUS PATENT APPLI-
CATION

Where there is no evidence of expressed intent or con-
duct by inventor to abandon his invention, delay in reapply-
ing for patent after abandonment of a previous application 
does not constitute abandonment under 35 U.S.C. 102(c). 
Petersen v. Fee Int'l, Ltd., 381 F. Supp. 1071, 182 USPQ 
264 (W.D. Okla. 1974).

DISCLOSURE WITHOUT CLAIMING IN A PRIOR 
ISSUED PATENT

Any inference of abandonment (i.e., intent to dedicate to 
the public) of subject matter disclosed but not claimed in a 
previously issued patent is rebuttable by an application 
filed at any time before a statutory bar arises. Accordingly, 
a rejection of a claim of a patent application under 
35 U.S.C. 102(c) predicated solely on the issuance of a 
patent which discloses the subject matter of the claim in the 
application without claiming it would be improper, regard-
less of whether there is copendency between the applica-
tion at issue and the application which issued as the patent. 
In re Gibbs, 437 F.2d 486, 168 USPQ 578 (CCPA 1971).

ONLY WHEN THERE IS A PRIORITY CONTEST 
CAN A LAPSE OF TIME BAR A PATENT

The mere lapse of time will not bar a patent. The only 
exception is when there is a priority contest under  35 
U.S.C. 102(g) and applicant abandons, suppresses or con-
ceals the invention. Panduit Corp. v. Dennison Mfg. Co., 
774 F.2d 1082, 1101, 227 USPQ 337, 350 (Fed. Cir. 1985). 
Abandonment, suppression and concealment are treated by 
the courts under 35 U.S.S. 102(g). See  MPEP ? 2138.03 
for more information on this issue.

2135	35 U.S.C. 102(d) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

(d)	the invention was first patented or caused to be patented, or was 
the subject of an inventor's certificate, by the applicant  or his legal repre-
sentatives or assigns in a foreign country prior to the date of the applica-
tion for patent in this country on an application for patent or inventor's 
certificate filed more than twelve months before the filing of the applica-
tion in the United States.

*****

GENERAL REQUIREMENTS OF 35 U.S.C. 102(d)

35 U.S.C. 102(d) establishes four conditions which, if all 
are present, establish a bar against the granting of a patent 
in this country:

(A)	The foreign application must be filed more than 
12 months before the effective U.S. filing date (See  MPEP 
? 706.02 regarding effective U.S. filing date of an applica-
tion);

(B)	The foreign application must have been filed by 
the same applicant as in the United States or by his or her 
legal representatives or assigns.

(C)	The foreign patent or inventor's certificate must 
be actually granted (e.g., by sealing of the papers in Great 
Britain) before the U.S. filing date. It need not be pub-
lished.

(D)	The same invention must be involved.

If such a foreign patent or inventor's certificate is dis-
covered by the examiner, the rejection is made under 
35 U.S.C. 102(d) on the ground of statutory bar. See MPEP 
? 2135.01 for further clarification of each of the four 
requirements of  35 U.S.C. 102(d).

2135.01	The Four Requirements of 35 
U.S.C. 102(d)  [R-1]

I.	FOREIGN APPLICATION MUST BE FILED 
MORE THAN 12 MONTHS BEFORE THE 
EFFECTIVE U.S. FILING DATE

A.	An Anniversary Date Ending on a Weekend or 
Holiday Results in an Extension to the Next 
Business Day

The U.S. application is filed in time to prevent a 
35 U.S.C. 102(d) bar from arising if it is filed on the 1 year 
anniversary date of the filing date of the foreign applica-
tion. If this day is a Saturday, Sunday or Federal holiday, 
the year would be extended to the following business day. 
See Ex parte Olah, 131 USPQ 41 (Bd. App. 1960.)  Despite 
changes to  37 CFR 1.6(a)(2) and 1.10, which require the 
PTO to accord a filing date to an application as of the date 
of deposit as "Express Mail" with the U.S. Postal Service in 
accordance with 37 CFR 1.10 (e.g., a Saturday filing date), 
the rule changes do not affect applicant's concurrent right 
to defer the filing of an application until the next business 
day when the last day for "taking any action" falls on a Sat-
urday, Sunday, or a Federal holiday (e.g., the last day of the 
1-year grace period falls on a Saturday).

B.	A Continuation-in-Part Breaks the Chain of  
Priority as to Foreign as Well as U.S. Parents

In the case where applicant files a foreign application, 
later files a U.S. application claiming priority based on the 
foreign application, and then files a continuation-in-part 
(CIP) application whose claims are not entitled to the filing 
date of the U.S. parent, the effective filing date is the filing 
date of the CIP and applicant cannot obtain the benefit of 
either the U.S. parent or foreign application filing dates. In 
re Van Langenhoven, 458 F.2d 132, 137, 173 USPQ 426, 
429 (CCPA 1972). If the foreign application issues into a 
patent before the filing date of the CIP, it may be used in a  
35 U.S.C. 102(d)/103 rejection if the subject matter added 
to the CIP does not render the claims nonobvious over the 
foreign patent. Ex parte Appeal No. 242-47, 196 USPQ 828 
(Bd. App. 1976) (Foreign patent can be combined with 
other prior art to bar a U.S. patent in an obviousness rejec-
tion based on  35 U.S.C. 102(d)/103).

II.	FOREIGN APPLICATION MUST HAVE BEEN 
FILED BY SAME APPLICANT, HIS OR HER 
LEGAL REPRESENTATIVE OR ASSIGNS

Note that where the U.S. application was made by two or 
more inventors, it is permissible for these inventors to 
claim priority from separate applications, each to one of the 
inventors or a subcombination of inventors. For instance, a 
U.S. application naming inventors A and B may be entitled 
to priority from one application to A and one to B filed in a 
foreign country.

III.	THE FOREIGN PATENT OR INVENTOR'S 
CERTIFICATE WAS ACTUALLY GRANTED 
BEFORE THE U.S. FILING DATE

A.	To Be "Patented" an Exclusionary Right Must Be 
Awarded to the Applicant

"Patented" means "a formal bestowal of patent rights 
from the sovereign to the applicant." In re Monks, 588 F.2d 
308, 310, 200 USPQ 129, 131 (CCPA 1978); American 
Infra-Red Radiant Co. v. Lambert Indus., 360 F.2d 977, 149 
USPQ 722 (8th Cir.), cert. denied, 385 U.S. 920 (1966) 
(German Gebrauchsmuster petty patent was held to be a 
patent usable in a  35 U.S.C. 102(d) rejection. Gebrauch-
mustern are not examined and only grant a 6-year patent 
term. However, except as to duration, the exclusionary 
patent right granted is as extensive as in the U.S.).

B.	A Published Application Is Not a "Patent"

An application must issue into a patent before it can be 
applied in a  35 U.S.C. 102(d) rejection. Ex parte Fujishiro, 
199 USPQ 36 (Bd. App. 1977) ("Patenting," within the 
meaning of  35 U.S.C. 102(d), does not occur upon laying 
open of a Japanese utility model application (kokai or 
kohyo)); Ex parte Links, 184 USPQ 429 (Bd. App. 1974) 
(German applications, which have not yet been published 
for opposition, are published in the form of printed docu-
ments called Offenlegungsschriften 18 months after filing. 
These applications are unexamined or in the process of 
being examined at the time of publication. The Board held 
that an Offenlegungsschrift is not a patent under  35 U.S.C. 
102(d) even though some provisional rights are granted. 
The *>Board< explained that the provisional rights are 
minimal and do not come into force if the application is 
withdrawn or refused.).

C.	An Allowed Application Can Be a "Patent" for 
Purposes of 35 U.S.C. 102(d) as of the Date 
Published for Opposition Even Though It Has Not 
Yet Been Granted as a Patent

An examined application which has been allowed by the 
examiner and published to allow the public to oppose the 
grant of a patent has been held to be a "patent" for purposes 
of rejection under  35 U.S.C. 102(d) as of the date of publi-
cation for opposition if substantial provisional enforcement 
rights arise. Ex parte Beik, 161 USPQ 795 (Bd. App. 1968) 
(This case dealt with examined German applications. After 
a determination that an application is allowable, the appli-
cation is published in the form of a printed document called 
an Auslegeschrift. The publication begins a period of oppo-
sition were the public can present evidence showing unpat-
entability. Provisional patent rights are granted which are 
substantially the same as those available once the opposi-
tion period is over and the patent is granted. The Board 
found that an Auslegeschrift provides the legal effect of a 
patent for purposes of rejection under  35 U.S.C. 102(d).).

D.	Grant Occurs when Patent Becomes Enforceable

The critical date of a foreign patent as a reference under  
35 U.S.C. 102(d) is the date the patent becomes enforceable 
(issued, sealed or granted). In re Monks, 588 F.2d 308, 310, 
200 USPQ 129, 131 (CCPA 1978) (British reference 
became available as prior art on date the patent was 
"sealed" because as of this date applicant had the right to 
exclude others from making, using or selling the claimed 
invention.). 

E.	35 U.S.C. 102(d) Applies as of Grant Date Even If 
There Is a Period of Secrecy After Patent Grant 

A period of secrecy after granting the patent, as in Bel-
gium and Spain, has been held to have no effect in connec-
tion with  35 U.S.C. 102(d). These patents are usable in 
rejections under  35 U.S.C. 102(d) as of the date patent 
rights are granted. In re Kathawala, 9 F.3d 942, 28 
USPQ2d 1789 (Fed. Cir. 1993) (An invention is "patented" 
for purposes of  35 U.S.C. 102(d) when the patentee's rights 
under the patent become fixed. The fact that applicant's 
Spanish application was not published until after the U.S. 
filing date is immaterial since the Spanish patent was 
granted before U.S. filing.); Gramme Elec. Co. v. Arnoux 
and Hochhausen Elec. Co., 17 F. 838, 1883 C.D. 418 
(S.D.N.Y. 1883) (Rejection made under a predecessor of  
35 U.S.C. 102(d) based on an Austrian patent granted an 
exclusionary right for 1 year but was kept secret, at the 
option of the patentee, for that period. The court held that 
the Austrian patent grant date was the relevant date under 
the statute for purposes of 35 U.S.C. 102(d) but that the 
patent could not have been used to in a rejection under  
35 U.S.C. 102(a) or (b).);   In re Talbott, 443 F.2d 1397, 170 
USPQ 281 (CCPA 1971) (Applicant cannot avoid a 
35 U.S.C. 102(d) rejection by exercising an option to keep 
the subject matter of a German Gebrauchsmuster (petty 
patent) in secrecy until time of U.S. filing.). 

IV.	THE SAME INVENTION MUST BE 
INVOLVED

"Same Invention" Means That the Application Claims 
Could Hsve Been Presented in the Foreign Patent

Under 35 U.S.C. 102(d), the "invention... patented" in 
the foreign country must be the same as the invention 
sought to be patented in the U.S. When the foreign patent 
contains the same claims as the U.S. application, there is no 
question that "the invention was first patented... in a foreign 
country." In re Kathawala, 9 F.3d 942, 945, 28 USPQ2d 
1785, 1787 (Fed. Cir. 1993). However, the claims need not 
be identical or even within the same statutory class. If 
applicant is granted a foreign patent which fully discloses 
the invention and which gives applicant a number of differ-
ent claiming options in the U.S., the reference in 35 U.S.C. 
102(d) to " `invention... patented' necessarily includes all 
the disclosed aspects of the invention. Thus, the section 
102(d) bar applies regardless whether the foreign patent 
contains claims to less than all aspects of the invention." 9 
F.3d at 946, 28 USPQ2d at 1788. In essence, a 35 U.S.C. 
102(d) rejection applies if applicant's foreign application 
supports the subject matter of the U.S. claims. In re Katha-
wala, 9 F.3d 942, 28 USPQ2d 1785 (Fed. Cir. 1993) 
(Applicant was granted a Spanish patent claiming a method 
of making a composition. The patent disclosed compounds, 
methods of use and processes of making the compounds. 
After the Spanish patent was granted, the applicant filed a 
U.S. application with claims directed to the compound but 
not the process of making it. The Federal Circuit held that it 
did not matter that the claims in the U.S. application were 
directed to the composition instead of the process because 
the foreign specification would have supported claims to 
the composition. It was immaterial that the formulations 
were unpatentable pharmaceutical compositions in Spain.).

2136	35 U.S.C. 102(e) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless-

*****

(e)	the invention was described in a patent granted on an applica-
tion for patent by another filed in the United States before the invention 
thereof by the applicant for patent, or on an international application by 
another who has fulfilled the requirements of paragraphs (1), (2), and (4) 
of section 371(c) of this title before the invention thereof by the applicant 
for patent.

*****

ONLY U.S. PATENTS AND SIRS ARE ELIGIBLE AS 
PRIOR ART UNDER 35 U.S.C. 102(e)

The reference must be a U.S. patent to be eligible for use 
in a 35 U.S.C. 102(e) rejection. Ex parte Smolka, 207 
USPQ 232 (Bd. App. 1980) (A foreign patent document 
with priority back to an abandoned U.S. application cannot 
be the basis for a 35 U.S.C. 102(e) rejection. The foreign 
document cannot be prior art until it is patented or pub-
lished.). Statutory Invention Registrations (SIRS)  can also 
be used in 35 U.S.C. 102(e) rejections as of their filing 
dates.

DEFENSIVE PUBLICATIONS ARE NOT PRIOR 
ART AS OF THEIR FILING DATE

A defensive publication is not a patent, it is a publica-
tion. Therefore, it is prior art only as of its publication date. 
Ex parte Osmond, 191 USPQ 334 (Bd. App. 1973) (Exam-
iner rejected the claims over Defensive Publication T-
858,018 issued by the PTO to Jacobson. The examiner 
made a 35 U.S.C. 102(a) rejection contending that a defen-
sive publication can be used as a reference under 35 U.S.C. 
102(a) as of its filing date. This position was authorized at 
that time by the MPEP and a Commissioner's Notice estab-
lishing the Defensive Publication Program. The Board 
found that in order for a 35 U.S.C. 102(a) rejection to 
apply, the reference must be of public knowledge and a 
Defensive Publication is not public knowledge at the time 
of its filing. Thus, the Board reversed the rejection. The 
Board also found that 35 U.S.C. 102(e) could not be used 
as a basis for rejection because the use of Defensive Publi-
cations as of their filing dates was not supported by section 
102(e).) See MPEP ? 711.06(a) for more information on 
Defensive Publications as references.

2136.01	Status of U.S. Patent as a Reference 
Before and After  Issuance

WHEN THERE IS NO COMMON ASSIGNEE OR 
INVENTOR, AN APPLICATION MUST ISSUE AS A 
PATENT BEFORE IT IS AVAILABLE AS PRIOR 
ART UNDER 35 U.S.C. 102(e)

Generally, a U.S. patent must issue before it can be used 
as a reference in a 35 U.S.C. 102(e) rejection. Ex parte 
Smolka, 207 USPQ 232 (Bd. App. 1980) (An application to 
Smolka and Schwuger was rejected over 35 U.S.C. 102(e) 
based on a pending U.S. application to Corkill whose filing 
date antedated the Smolka et al. application. A German 
application corresponding to the Corkill application had 
been published, but did not antedate the effective filing date 
of the Smolka et al. application. The Board reversed the 
rejection holding that a U.S. patent had to be issued to 
Corkill before it could become available as prior art under  
35 U.S.C. 102(e). There was no common assignee nor any 
common inventor between the two applications.).

WHEN THERE IS A COMMON ASSIGNEE OR 
INVENTOR, A PROVISIONAL 35 U.S.C. 102(e) 
REJECTION OVER AN EARLIER FILED APPLICA-
TION CAN BE MADE

Based on the assumption that an application will ripen 
into a U.S. patent, it is permissible to provisionally reject a 
later application over an earlier application under 35 U.S.C. 
102(e). In re Irish, 433 F.2d 1342, 167 USPQ 764 (CCPA 
1970). Such a provisional rejection "serves to put applicant 
on notice at the earliest possible time of the possible prior 
art relationship between copending applications" and gives 
applicant the fullest opportunity to overcome the rejection 
by amendment or submission of evidence. In addition, 
since both applications are pending and usually have the 
same assignee, more options are available to applicant for 
overcoming the provisional rejection than if the other appli-
cation were already issued. Ex parte Bartfeld, 16 USPQ2d 
1714 (Bd. Pat. App. & Int. 1990) aff'd on other grounds, 
925 F.2d 1450,  17 USPQ2d 1885 (Fed. Cir. 1991). Note 
that provisional rejections over 35 U.S.C. 102(e) are only 
authorized when there is a common inventor or assignee, 
otherwise the copending application must remain confiden-
tial.  MPEP ? 706.02(f) and  ? 706.02(k) discuss the proce-
dures to be used in provisional rejections over 35 U.S.C. 
102(e) and 103.

2136.02	Content of the Prior Art Available 
Against the Claims 

A 35 U.S.C. 102(e) REJECTION MAY RELY ON ANY 
PART OF THE PATENT DISCLOSURE 

Under  35 U.S.C. 102(e), the entire disclosure of a U.S. 
patent having an earlier filing date can be relied on to reject 
the claims. Sun Studs, Inc. v. ATA Equip. Leasing, Inc., 872 
F.2d 978, 983, 10 USPQ2d 1338, 1342 (Fed. Cir. 1989).

U.S. PATENT REFERENCE MUST ITSELF CON-
TAIN THE SUBJECT MATTER RELIED ON IN THE 
REJECTION

When a U.S. patent is used to reject claims under 
35 U.S.C. 102(e), the disclosure relied on in the rejection 
must be present in the issued patent. It is the filing date of 
the U.S. patent being relied on as the critical reference date 
and subject matter not included in the patent itself can only 
be used when that subject matter becomes public. Portions 
of the patent application which were canceled are not part 
of the patent and thus cannot be relied on in a  35 U.S.C. 
102(e) rejection over the issued patent. Ex Parte Stalego, 
154 USPQ 52 (Bd. App. 1966). Likewise, subject matter 
which is disclosed in a parent application, but not included 
in the child continuation-in-part (CIP) cannot be relied on 
in a  35 U.S.C. 102(e) rejection over the issued CIP. In re 
Lund, 376 F.2d 982, 153 USPQ 625 (CCPA 1967) (The 
examiner made a 35 U.S.C. 102(e) rejection over an issued 
U.S. patent which was a continuation-in-part (CIP). The 
parent application of the U.S. patent reference contained an 
example II which was not carried over to the CIP. The court 
held that the subject matter embodied in the canceled 
example II could not be relied on as of either parent or child 
filing date. Thus, the use of example II subject matter to 
reject the claims under 35 U.S.C. 102(e) was improper.).

THE SUPREME COURT HAS AUTHORIZED 
35 U.S.C. 103 REJECTIONS BASED ON 35 U.S.C. 
102(e)

U.S. patents may be used as of their filing dates to show 
that the claimed subject matter is anticipated or obvious. 
Obviousness can be shown by combining other prior art 
with the U.S. patent reference in a 35 U.S.C. 103 rejection. 
Hazeltine Research v. Brenner, 382 U.S. 252, 147 USPQ 
429 (1965).

2136.03	Critical Reference Date  [R-1]

I.	FOREIGN PRIORITY DATE

Reference's Foreign Priority Date Under 35 U.S.C. 
119(a)-(d) Cannot Be Used as the 35 U.S.C. 102(e) 
Reference Date

A U.S. patent reference is effective prior art as of its U.S. 
filing date.  35 U.S.C. 119(a)-(d) does not modify section 
102(e) which is explicitly limited to patent references "filed 
in the United States before the invention thereof by the 
applicant" (emphasis added). Therefore, the foreign prior-
ity date of the reference under 35 U.S.C. 119(a)-(d) cannot 
be used to antedate the application filing date. In contrast, 
applicant may be able to overcome the 35 U.S.C. 102(e) 
rejection by proving he or she is entitled to his or her own  
35 U.S.C. 119 priority date which is earlier than the refer-
ence's U.S. filing date. In re Hilmer, 359 F.2d 859, 149 
USPQ 480 (CCPA 1966) (Hilmer I) (Applicant filed an 
application with a right of priority to a German application. 
The examiner rejected the claims over a U.S. patent to Hab-
icht based on its Swiss priority date. The U.S. filing date of 
Habicht was later than the application's German priority 
date. The court held that the reference's Swiss priority date 
could not be relied on in a 35 U.S.C. 102(e) rejection.  
Because the U.S. filing date of Habicht was later than the 
earli est effective filing date (German priority date) of the 
application, the rejection was reversed.). See MPEP 
? 201.15 for information on procedures to be followed in 
considering applicant's right of priority. 

II.	>CONTINUATION OF AN< INTERNATIONAL 
(PCT) **>APPLICATION<

**

Where a U.S. application filed under 35 U.S.C. 111(a) 
claims the benefit of the filing date of a copending PCT 
international application under 35 U.S.C. 120, its effective 
date as a reference under 35 U.S.C. 102(e) is the **>U.S. 
filing date of the 35 U.S.C. 111(a) application and not the 
international filing date.  When< a U.S. national stage 
application filed under 35 U.S.C. 371 becomes a U.S. 
patent, the 35 U.S.C. 102(e) date of the U.S. Patent as a 
prior art reference is the date applicant fulfilled the require-
ments of 35 U.S.C. 371(c)(1), (c)(2), and (c)(4). See MPEP 
? 715 and  ? 1896.

III.	PRIORITY FROM PROVISIONAL APPLICA-
TION UNDER 35 U.S.C. 119(e)

The 35 U.S.C. 102(e) critical reference date of a U.S. 
patent entitled to the benefit of the filing date of a provi-
sional application under 35 U.S.C. 119(e) is the filing date 
of the provisional application, except in the case of a U.S. 
patent granted on an international (PCT) application in 
which the requirements of paragraphs (1), (2) and (4) of 
35 U.S.C. 371(c) have been fulfilled. By the terms of 
35 U.S.C. 102(e), the critical reference date of a U.S. patent 
granted on such a  35 U.S.C. 371 application is the date on 
which paragraphs (c)(1), (c)(2) and (c)(4) have been ful-
filled, not the filing date of the provisional application.

IV.	PARENT'S FILING DATE WHEN REFER-
ENCE IS A CONTINUATION-IN-PART OF 
THE PARENT

Filing Date of U.S. Parent Application Can Only Be Used 
as the 35 U.S.C. 102(e) Date If It Supports the Claims of 
the Issued Child

In order to carry back the 35 U.S.C. 102(e) critical date 
of the U.S. patent reference to the filing date of a parent 
application, the parent application must (A) have a right of 
priority to the earlier date under 35 U.S.C. 120 and (B) sup-
port the invention claimed as required by 35 U.S.C. 112, 
first paragraph. "For if a patent could not theoretically have 
issued the day the application was filed, it is not entitled to 
be used against another as `secret prior art' " under 
35 U.S.C. 102(e). In re Wertheim, 646 F.2d 527, 537, 209 
USPQ 554, 564 (CCPA 1981) (The examiner made a 
35 U.S.C. 103 rejection over a U.S. patent to Pfluger. The 
Pfluger patent (Pfluger IV) was the child of a string of 
abandoned parent applications (Pfluger I, the first applica-
tion, Pfluger II and III, both CIPs). Pfluger IV was a contin-
uation of Pfluger III. The court characterized the contents 
of the applications as follows: Pfluger I - subject matter A, 
II-AB, III-ABC, IV-ABC. ABC anticipated the claims of 
the examined application, but the filing date of III was later 
than the application filing date. So the examiner reached 
back to "A" in Pfluger I and combined this disclosure with 
another reference to establish obviousness. The court held 
that the examiner impermissibly carried over "A" and 
should have instead determined which of the parent appli-
cations contained the subject matter which made Pfluger 
patentable. Only if B and C were not claimed, or at least not 
critical to the patentability of Pfluger IV, could the filing 
date of Pfluger I be used. The court reversed the rejection 
based on a determination that Pfluger IV was only entitled 
to the Pfluger III filing date. The added new matter (C) was 
critical to the claims of the issued patent.). Note that In re 
Wertheim modified the holding of In re Lund, 376 F.2d 982, 
153 USPQ 625 (CCPA 1967) as to "carrying back" the sub-
ject matter to the parent applications.

See also Ex parte Gilderdale, 1990 Pat. App. LEXIS 25 
(Bd. Pat. App. & Inter. Appeal no. 89-0352) (The examiner 
made a 35 U.S.C. 102(e) rejection over a U.S. patent to 
Hernandez   et al. Hernandez   et al. was a continuation of a 
continuation-in-part. Both the parent and grandparent had 
been abandoned. The parent listed a different inventive 
entity but supported the subject matter of the child's claims. 
The parent was filed on the same day as the examined 
application and thus no 35 U.S.C. 102(e) rejection could be 
made based on the parent's filing date. The Board reversed 
the rejection, explaining that the Hernandez patent was 
entitled to the filing date of its parent, as the parent sup-
ported the patent claims and 35 U.S.C. 120 was satisfied. 
Under 35 U.S.C. 120, an application can claim the benefit 
of an earlier filing date even if not all inventors are the 
same. However, Hernandez was not entitled to the grand-
parent filing date because the parent and child applications 
contained new matter as compared to the grandparent.). 

Compare Ex parte Ebata, 19 USPQ2d 1952 (Bd. Pat. 
App. & Inter. 1991) (The claims were directed to a method 
of administering a salt of lysocellin to animals. A 35 U.S.C. 
102(e) rejection was made over Martin. Martin was a con-
tinuation of an application which was in turn a continua-
tion-in-part of an abandoned application. The grandparent 
application disclosed administering a manganese complex 
of lysocellin to animals. The Board found that "the new 
matter relates to additional forms of lysocellin which are 
useful in Martin's process, i.e., species or embodiments 
other than the manganese complex. This is far different 
from adding limitations which are required or necessary 
for patentability." Unlike the situation in In re Wertheim, 
Martin's invention was patentable as presented in the 
grandparent application.).

V.	DATE OF CONCEPTION OR REDUCTION TO 
PRACTICE

35 U.S.C. 102(e) Reference Date Is the Filing Date Not 
Date of Patentee's Conception or Reduction to Practice 

If the U.S. patent applied as a 35 U.S.C. 102(e) reference 
discloses, but does not claim the subject matter of the 
claims being examined or an obvious variant, the patent is 
not prior art under 35 U.S.C. 102(g). When the cases are 
not in interference, the effective date of the reference U.S. 
patent as prior art is its filing date in the United States, as 
stated in 35 U.S.C. 102(e). The date that the prior art U.S. 
patent subject matter was conceived or reduced to practice 
is of no importance when  35 U.S.C. 102(g) is not at issue. 
Sun Studs, Inc. v. ATA Equip. Leasing, Inc., 872 F.2d 978, 
983, 10 USPQ2d 1338, 1342 (Fed. Cir. 1989) (The defen-
dant sought to invalidate patents issued to Mason and Sohn 
assigned to Sun Studs. The earliest of these patents issued 
in June 1973. A U.S. patent to Mouat was found which 
issued in March 1976 and which disclosed the invention of 
Mason and Sohn. While the patent to Mouat issued after 
the Mason and Sohn patents, it was filed 7 months earlier 
than the earliest of the Mason and Sohn patents. Sun Studs 
submitted affidavits showing conception in 1969 and dili-
gence to the constructive reduction to practice and there-
fore antedated the patent to Mouat. The defendant sought to 
show that Mouat conceived the invention in 1966. The 
court held that conception of the subject matter of the refer-
ence only becomes an issue when the claims of the conflict-
ing patents cover inventions which are the same or obvious 
over one another. When 35 U.S.C. 102(e) applies but not  
35 U.S.C. 102(g), the filing date of the prior art patent is the 
earliest date that can be used to reject or invalidate claims.).

2136.04	Different Inventive Entity; 
Meaning of "By Another" 

IF THERE IS ANY DIFFERENCE IN THE INVEN-
TIVE ENTITY, THE PATENT REFERENCE IS "BY 
ANOTHER"

"Another" means other than applicants, In re Land, 368 
F.2d 866,  151 USPQ 621 (CCPA 1966), in other words, a 
different inventive entity. The inventive entity is different if 
not all inventors are the same. The fact that the application 
and patent have one or more inventors in common is imma-
terial. Ex parte DesOrmeaux, 25 USPQ2d 2040 (Bd. Pat. 
App. & Inter. 1992) (The examiner made a 35 U.S.C. 
102(e) rejection based on an issued U.S. patent to three 
inventors. The rejected application was a continuation-in-
part of the issued parent with an extra inventor. The Board 
found that the patent was "by another" and thus could be 
used in a 35 U.S.C. 102(e)/103 rejection of the applica-
tion.).

A DIFFERENT INVENTIVE ENTITY IS PRIMA 
FACIE EVIDENCE THAT THE U.S. PATENT IS "BY 
ANOTHER" 

As stated by the House and Senate reports on the bills 
enacting section 35 U.S.C. 102(e), this subsection of 102 
codifies the Milburn rule of Milburn v. Davis- Bournon-
ville, 270 U.S. 390 (1926). The Milburn rule authorized the 
use of a U.S. patent containing a disclosure of the invention 
as a reference against a later filed application as of the U.S. 
patent filing date. The existence of an earlier filed U.S. 
application containing the subject matter claimed in the 
application being examined indicates that applicant was not 
the first inventor. Therefore, a U.S. patent by a different 
inventive entity, whether or not the application shares some 
inventors in common with the patent, is prima facie evi-
dence that the invention was made "by another" as set forth 
in section 102(e). In re Mathews, 408 F.2d 1393, 161 USPQ 
276 (CCPA 1969); In re Facius, 408 F.2d 1396, 161 USPQ 
294 (CCPA 1969); Ex parte DesOrmeaux, 25 USPQ2d 
2040 (Bd. Pat. App. & Inter. 1992). See MPEP ? 2136.05 
for discussion of methods of overcoming 102(e) rejections.

2136.05	Overcoming a Rejection Under  
35 U.S.C. 102(e)  [R-1]

A 35 U.S.C. 102(e) REJECTION CAN BE 
OVERCOME BY ANTEDATING THE FILING DATE 
OR SHOWING THAT DISCLOSURE RELIED ON IS 
APPLICANT'S OWN WORK

When a prior U.S. patent is not a statutory bar, a 
35 U.S.C. 102(e) rejection can be overcome by antedating 
the filing date (see  MPEP ? 2136.03 regarding critical ref-
erence date of a U.S. patent) of the U.S. patent reference 
by submitting an affidavit or declaration under 37 CFR 
1.131 or by submitting an affidavit or declaration under 
37 CFR 1.132 establishing that the relevant disclosure is 
applicant's own work. In re Mathews, 408 F.2d 1393, 161 
USPQ 276 (CCPA 1969). The filing date can also be ante-
dated by applicant's earlier foreign priority application or 
provisional application if 35 U.S.C. 119 is met and the for-
eign application or provisional application "supports" (con-
forms to 35 U.S.C. 112, first paragraph, requirements) all 
the claims of the U.S. application. In re Gosteli, 872 F.2d 
1008, 10 USPQ2d 1614 (Fed. Cir. 1989). But a prior appli-
cation which was not copending with the application at 
issue cannot be used to antedate a reference. In re Costello, 
717 F.2d 1346, 219 USPQ 389 (Fed. Cir. 1983). A terminal 
disclaimer also does not overcome a 35 U.S.C. 102(e) 
rejection. >See, e.g.,<In re Bartfeld, 925 F.2d 1415, 17 
USPQ2d 1885 (Fed. Cir. 1991)**. 

See  MPEP ? 706.02(b) for a list of methods which can 
be used to overcome rejections based on 35 U.S.C. 102(e) 
rejections. For information on the required contents of a  
37 CFR 1.131 affidavit or declaration and the situations in 
which such affidavits and declarations are permitted see  
MPEP ? 715. An affidavit or declaration is not appropriate 
if the reference describes applicant's own work. In this 
case, applicant must submit an affidavit or declaration 
under 37 CFR 1.132. See the next paragraph for more 
information concerning the requirements of  37 CFR 1.132 
affidavits and declarations. 

A 35 U.S.C. 102(e) REJECTION CAN BE OVER-
COME BY SHOWING THE PATENT IS DESCRIB-
ING APPLICANT'S OWN WORK

"The fact that an application has named a different 
inventive entity than a patent does not necessarily make 
that patent prior art." Applied Materials Inc. v. Gemini 
Research Corp., 835 F.2d 279, 15 USPQ2d 1816 (Fed. Cir. 
1988). The issue turns on what the evidence of record 
shows as to who invented the subject matter. In re Whittle, 
454 F.2d 1193, 1195, 172 USPQ 535, 537 (CCPA 1972). In 
fact, even if applicant's work was publicly disclosed prior 
to his or her application, applicant's own work may not be 
used against him or her unless there is a time bar under 
35 U.S.C. 102(b). In re DeBaun, 687 F.2d 459, 214 USPQ 
933 (CCPA 1982) (citing In re Katz, 687 F.2d 450, 215 
USPQ 14 (CCPA 1982)). Therefore, when the unclaimed 
subject matter of a patent is applicant's own invention, 
applicant may overcome a prima facie case based on the 
patent by showing that the patent disclosure is a description 
of applicant's own previous work. Such a showing can be 
made by proving that the patentee was associated with 
applicant (e.g. worked for the same company) and learned 
of applicant's invention from applicant. In re Mathews, 408 
F.2d 1393, 161 USPQ 276 (CCPA 1969). In the situation 
where one application is first filed by inventor X and then a 
later application is filed by X&Y, it must be proven that the 
joint invention was made first, was thereafter described in 
the sole applicant's patent and then the joint application was 
filed. In re Land, 368 F.2d 866, 151 USPQ 621 (CCPA 
1966).

In In re Land, separate U.S. patents to Rogers and to 
Land were used to reject a joint application to Rogers and 
Land under 35 U.S.C. 102(e)/103. The inventors worked 
for the same company (Polaroid) and in the same labora-
tory. All the patents flowed from the same research. In 
addition, the patent applications were prepared by the same 
attorneys, were interrelated and contained cross-references 
to each other. The court affirmed the rejection because (1) 
the inventive entities of the patents (one to Rogers and one 
to Land) were different from the inventive entity of the 
joint application (Rogers and Land) and (2) Land and Rog-
ers brought their knowledge of their individual work with 
them when they made the joint invention. There was no 
indication that the portions of the references relied on dis-
closed anything they did jointly. Neither was there any 
showing that what they did   jointly was done before the fil-
ing of the reference patent applications.

See also   In re Carreira, 532 F.2d 1356, 189 USPQ 461 
(CCPA 1976) (The examiner rejected claims to a joint 
application to Carreira, Kyrakakis, Solodar, and Labana 
under  35 U.S.C. 102(e) and 103 in view of a U.S. patent 
issued to Tulagin and Carreira or a patent issued to Clark. 
The applicants submitted declarations under 37 CFR 1.132 
by Tulagin and Clark in which each declarant stated he was 
"not the inventor of the use of compounds having a 
hydroxyl group in a position ortho to an azo linkage." The 
court held that these statements were vague and inconclu-
sive because the declarants did not disclose the use of this 
generic compound but rather species of this generic com-
pound in their patents and it was the species which met the 
claims. The declaration that each did not invent the use of 
the generic compound does not establish that Tulagin and 
Clark did not invent the use of the species.) 

MPEP ? 715.01(a),  ? 715.01(c), and  ? 716.10 set forth 
more information pertaining to the contents and uses of 
affidavits and declarations under  37 CFR 1.132 for ante-
dating references.  >See MPEP ? 706.02(l)(1) for informa-
tion pertaining to rejections under 35 U.S.C. 102(e)/103  
and the applicability of 35 U.S.C. 103(c).<

APPLICANT NEED NOT SHOW DILIGENCE OR 
REDUCTION TO PRACTICE WHEN THE SUBJECT 
MATTER DISCLOSED IN THE REFERENCE IS 
APPLICANT'S OWN WORK

When the U.S. patent reference reflects applicant's own 
work, applicant need not prove diligence or reduction to 
practice to establish that he or she invented the subject mat-
ter disclosed in the patent reference. A showing that the ref-
erence disclosure arose from applicant's work coupled with 
a showing of conception by the applicant before the filing 
date of the reference will overcome the 35 U.S.C. 102(e) 
rejection. The showing can be made by submission of an 
affidavit by the inventor under 37 CFR 1.132. The other 
patentees need not submit an affidavit disclaiming inven-
torship, but, if submitted, a disclaimer by all other patentees 
should be considered by the examiner. In re DeBaun, 687 
F.2d 459, 214 USPQ 933 (CCPA 1982) (Declaration sub-
mitted by DeBaun stated that he was the inventor of subject 
matter disclosed in the U.S. patent reference of DeBaun 
and Noll. Exhibits were attached to the declaration showing 
conception and included drawings DeBaun had prepared 
and given to counsel for purposes of preparing the applica-
tion which issued as the reference patent. The court held 
that, even though the evidence was not sufficient to ante-
date the prior art patent under 37 CFR 1.131, diligence and/
or reduction to practice was not required to show DeBaun 
invented the subject matter. Declarant's statement that he 
conceived the invention first was enough to overcome the  
35 U.S.C. 102(e) rejection.). 

CLAIMING OF INDIVIDUAL ELEMENTS OR SUB-
COMBINATIONS IN A COMBINATION CLAIM OF 
THE REFERENCE PATENT DOES NOT ITSELF 
ESTABLISH THAT THE PATENTEE INVENTED 
THOSE ELEMENTS

The existence of combination claims in a U.S. patent is 
not evidence that the patentee invented the individual ele-
ments or subcombinations included if the elements and 
subcombinations are not separately claimed apart from the 
combination. In re DeBaun, 687 F.2d 459, 214 USPQ 933 
(CCPA 1982) (citing In re Facius, 408 F.2d 1396, 1406, 
161 USPQ 294, 301 (CCPA 1969)).

See also In re Mathews, 408 F.2d 1393, 161 USPQ 276 
(CCPA 1969) (On September 15, 1961, Dewey filed an 
application disclosing and claiming a time delay protective 
device for an electric circuit. In disclosing the invention, 
Dewey completely described, but did not claim, a "gating 
means 19" invented by Mathews which was usable in the 
protective device. Dewey and Mathews were coworkers at 
General Electric Company, the assignee. Mathews filed his 
application on March 7, 1963, before the Dewey patent 
issued but almost 18 months after its filing. The Mathews 
application disclosed that "one illustration of a circuit 
embodying the present inven tion is shown in copending 
patent application S.N. 138,476-Dewey." The examiner 
used Dewey to reject all the Mathews claims under 
35 U.S.C. 102(e). In response, Mathews submitted an affi-
davit by Dewey under 37 CFR 1.132. In the affidavit, 
Dewey stated that he did not invent the gating means 19 but 
had learned of the gating means through Mathews and that 
GE attorneys had advised that the gating means be dis-
closed in Dewey's application to comply with 35 U.S.C. 
112, first paragraph. The examiner argued that the only way 
to overcome a 35 U.S.C. 102(e) rejection was by submit-
ting an affidavit or declaration under 37 CFR 1.131 to ante-
date the filing date of the reference. The court reversed the 
rejection, holding that the totality of the evidence on record 
showed that Dewey derived his knowledge from Mathews 
who is "the original, first and sole inventor.").

2137	35 U.S.C. 102(f) 

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

(f)	he did not himself invent the subject matter sought to be pat-
ented.

*****

Where it can be shown that an applicant "derived" an 
invention from another, a rejection under  35 U.S.C. 102(f) 
is proper. Ex parte Kusko, 215 USPQ 972, 974 (Bd. App. 
1981) ("most, if not all, determinations under section 
102(f) involve the question of whether one party derived an 
invention from another").

While derivation will bar the issuance of a patent to the 
deriver, a disclosure by the deriver, absent a bar under 
35 U.S.C. 102(b), will not bar the issuance of a patent to 
the party from which the subject matter was derived. In re 
Costello, 717 F.2d 1346, 1349, 219 USPQ 389, 390-91 
(Fed. Cir. 1983) ("[a] prior art reference that is not a statu-
tory bar may be overcome by two generally recognized 
methods": an affidavit under 37 CFR 1.131, or an affidavit 
under 37 CFR 1.132 "showing that the relevant disclosure 
is a description of the applicant's own work"); In re Facius, 
408 F.2d 1396, 1407, 161 USPQ 294, 302 (CCPA 1969) 
(subject matter incorporated into a patent that was brought 
to the attention of the patentee by applicant, and hence 
derived by the patentee from the applicant, is available for 
use against applicant unless applicant had actually invented 
the subject matter placed in the patent).

Where there is a published article identifying the author-
ship (MPEP ? 715.01(c)) or a patent identifying the  inven-
torship (MPEP ? 715.01(a)) that discloses subject matter 
being claimed in an application undergoing examination, 
the designation of authorship or inventorship does not raise 
a presumption of inventorship with respect to the subject 
matter disclosed in the article or with respect to the subject 
matter disclosed but not claimed in the patent so as to jus-
tify a rejection under 35 U.S.C. 102(f). However, it is 
incumbent upon the inventors named in the application, in 
reply to an inquiry regarding the appropriate inventorship 
under subsection (f), or to rebut a rejection under 35 U.S.C. 
102(a) or (e), to provide a satisfactory showing by way of 
affidavit under 37 CFR 1.132 that the inventorship of the 
application is correct in that the reference discloses subject 
matter invented by the applicant rather than derived from 
the author or patentee notwithstanding the authorship of the 
article or the inventorship of the patent. In re Katz, 687 F.2d 
450, 455, 215 USPQ 14, 18 (CCPA 1982) (inquiry is appro-
priate to clarify any ambiguity created by an article regard-
ing inventorship, and it is then incumbent upon the 
applicant to provide "a satisfactory showing that would 
lead to a reasonable conclusion that [applicant] is 
the?inventor" of the subject matter disclosed in the article 
and claimed in the application).

DERIVATION REQUIRES COMPLETE CONCEP-
TION BY ANOTHER AND COMMUNICATION TO 
THE ALLEGED DERIVER

"The mere fact that a claim recites the use of various 
components, each of which can be argumentatively 
assumed to be old, does not provide a proper basis for a 
rejection under 35 U.S.C. 102(f)." Ex parte Billottet, 192 
USPQ 413, 415 (Bd. App. 1976). Derivation requires com-
plete conception by another and communication of that 
conception by any means to the party charged with deriva-
tion prior to any date on which it can be shown that the one 
charged with derivation possessed knowledge of the inven-
tion. Kilbey v. Thiele, 199 USPQ 290, 294 (Bd. Pat. Inter. 
1978).

 See also Price v. Symsek, 988 F.2d 1187, 1190, 26 
USPQ2d 1031, 1033 (Fed. Cir. 1993); Hedgewick v. Akers, 
497 F.2d 905, 908, 182 USPQ 167, 169 (CCPA 1974).  
"Communication of a complete conception must be suffi-
cient to enable one of ordinary skill in the art to construct 
and successfully operate the invention." Hedgewick, 497 
F.2d at 908, 182 USPQ at 169. See also Gambro Lundia AB 
v. Baxter Healthcare Corp., 110 F.3d 1573, 1577, 42 
USPQ2d 1378, 1383 (Fed. Cir. 1997) (Issue in proving der-
ivation is "whether the communication enabled one of ordi-
nary skill in the art to make the patented invention.").

PARTY ALLEGING DERIVATION DOES NOT 
HAVE TO PROVE AN ACTUAL REDUCTION TO 
PRACTICE, DERIVATION OF PUBLIC KNOWL-
EDGE, OR DERIVATION IN THIS COUNTRY

The party alleging derivation "need not prove an actual 
reduction to practice in order to show derivation."   Scott v. 
Brandenburger, 216 USPQ 326, 327 (Bd. App. 1982). Fur-
thermore, the application of subsection (f) is not limited to 
public knowledge derived from another, and "the site of 
derivation need not be in this country to bar a deriver from 
patenting the subject matter." Ex parte Andresen, 212 
USPQ 100, 102 (Bd. App. 1981).

DERIVATION DISTINGUISHED FROM PRIORITY 
OF INVENTION

Although derivation and priority of invention both focus 
on inventorship, derivation addresses originality (i.e., 
who invented the subject matter), whereas priority 
focuses on which party first invented the subject matter. 
Price v. Symsek, 988 F.2d 1187, 1190, 26 USPQ2d 1031, 
1033 (Fed. Cir. 1993).

35 U.S.C. 102(f) MAY APPLY WHERE 35 U.S.C. 
102(a) AND 35 U.S.C. 102(e) ARE NOT AVAILABLE 
STATUTORY GROUNDS FOR REJECTION

35 U.S.C. 102(f) does not require an inquiry into the rel-
ative dates of a reference and the application, and therefore 
may be applicable where subsections (a) and (e) are not 
available for references having an effective date subsequent 
to the effective date of the application being examined. 
However for a reference having a date later than the date of 
the application some evidence may exist that the subject 
matter of the reference was derived from the applicant in 
view of the relative dates. Ex parte Kusko, 215 USPQ 972, 
974 (Bd. App. 1981) (The relative dates of the events are 
important in determining derivation; a publication dated 
more than a year after applicant's filing date that merely 
lists as literary coauthors individuals other than applicant is 
not the strong evidence needed to rebut a declaration by the 
applicant that he is the sole inventor.).

2137.01	Inventorship   [R-1]

The requirement that the applicant for a patent be the 
inventor is a characteristic of U.S. patent law not generally 
shared by other countries. Consequently, foreign applicants 
may misunderstand U.S. law regarding naming of the 
actual inventors causing an error in the inventorship of a 
U.S. application that may claim priority to a previous for-
eign application under 35 U.S.C. 119. A petition under  
37 CFR 1.48(a) is required to correct any error in naming 
the inventors in the U.S. application as filed.  MPEP 
? 201.03. Foreign applicants may need to be reminded of 
the requirement for identity of inventorship between a U.S. 
application and a 35 U.S.C. 119 priority application.  
MPEP ? 201.13. 

If a determination is made that the inventive entity 
named in a U.S. application is not correct, such as when a 
petition under 37 CFR 1.48(a) is not granted or is not 
entered for technical reasons, but the admission therein 
regarding the error in inventorship is uncontroverted, a 
rejection under  35 U.S.C. 102(f) should be made. 

EXECUTORS OF OATH OR DECLARATION 
UNDER 37 CFR 1.63 ARE PRESUMED TO BE THE 
INVENTORS

The party or parties executing an oath or declaration 
under  37 CFR 1.63 are presumed to be the inventors. 
Driscoll v. Cebalo, 5 USPQ2d 1477, 1481 (Bd. Pat. Inter. 
1982); In re DeBaun, 687 F.2d 459, 463, 214 USPQ 933, 
936 (CCPA 1982) (The inventor of an element, per se, and 
the inventor of that element as used in a combination may 
differ. "The existence of combination claims does not evi-
dence inventorship by the patentee of the individual ele-
ments or subcombinations thereof if the latter are not 
separately claimed apart from the combination." (quoting 
In re Facius, 408 F.2d 1396, 1406, 161 USPQ 294, 301 
(CCPA 1969) (emphasis in original)); Brader v. Schaeffer, 
193 USPQ 627, 631 (Bd. Pat. Inter. 1976) (in regard to an 
inventorship correction: "[a]s between inventors their word 
is normally taken as to who are the actual inventors" when 
there is no disagreement). 

AN INVENTOR MUST CONTRIBUTE TO THE 
CONCEPTION OF THE INVENTION

The definition for inventorship can be simply stated: 
"The threshold question in determining inventorship is who 
conceived the invention. Unless a person contributes to the 
conception of the invention, he is not an inventor. ? Inso-
far as defining an inventor is concerned, reduction to prac-
tice, per se, is irrelevant [except for simultaneous 
conception and reduction to practice, Fiers v. Revel, 984 
F.2d 1164, 1168, 25 USPQ2d 1601, 1604-05 (Fed. Cir. 
1993)]. One must contribute to the conception to be an 
inventor." In re Hardee, 223 USPQ 1122, 1123 (Comm'r 
Pat. 1984). See also Ex parte Smernoff, 215 USPQ 545, 547 
(Bd. App. 1982) ("one who suggests an idea of a result to 
be accomplished, rather than the means of accomplishing 
it, is not an coinventor"). See MPEP ? 2138.04 - ? 2138.05 
for a discussion of what evidence is required to establish 
conception or reduction to practice. 

AS LONG AS THE INVENTOR MAINTAINS 
INTELLECTUAL DOMINATION OVER MAKING 
THE INVENTION, IDEAS, SUGGESTIONS, AND 
MATERIALS MAY BE ADOPTED FROM OTHERS 

"In arriving at ? conception [the inventor] may consider 
and adopt ideas and materials derived from many sources 
? [such as] a suggestion from an employee, or hired con-
sultant ? so long as he maintains intellectual domination 
of the work of making the invention down to the successful 
testing, selecting or rejecting as he goes?even if such sug-
gestion [or material] proves to be the key that unlocks his 
problem." Morse v. Porter, 155 USPQ 280, 283 (Bd. Pat. 
Inter. 1965). See also New England Braiding Co. v. A.W. 
Chesterton Co., 970 F.2d 878, 883, 23 USPQ2d 1622, 1626 
(Fed. Cir. 1992) (Adoption of the ideas and materials from 
another can become a derivation.). 

THE INVENTOR IS NOT REQUIRED TO REDUCE 
THE INVENTION TO PRACTICE

Difficulties arise in separating members of a team effort, 
where each member of the team has contributed something, 
into those members that actually contributed to the concep-
tion of the invention, such as the physical structure or oper-
ative steps, from those members that merely acted under 
the direction and supervision of the conceivers. Fritsch v. 
Lin, 21 USPQ2d 1737, 1739 (Bd. Pat. App. & Inter. 1991) 
(The inventor "took no part in developing the proce-
dures?for expressing the EPO gene in mammalian host 
cells and isolating the resulting EPO product." However, "it 
is not essential for the inventor to be personally involved in 
carrying out process  steps?where implementation of 
those steps does not require the exercise of inventive 
skill."); In re DeBaun, 687 F.2d 459, 463, 214 USPQ 933, 
936 (CCPA 1982) ("there is no requirement that the inven-
tor be the one to reduce the invention to practice so long as 
the reduction to practice was done on his behalf").

See also Mattor v. Coolegem, 530 F.2d 1391, 1395, 189 
USPQ 201, 204 (CCPA 1976) (one following oral instruc-
tions is viewed as merely a technician); Tucker v. Naito, 
188 USPQ 260, 263 (Bd. Pat. Inter. 1975) (inventors need 
not "personally construct and test their invention"); Davis 
v. Carrier,  81 F.2d 250, 252, 28 USPQ 227, 229 (CCPA 
1936) (noninventor's work was merely that of a skilled 
mechanic carrying out the details of a plan devised by 
another). 

REQUIREMENTS FOR JOINT INVENTORSHIP

The inventive entity for a particular application is based 
on some contribution to at least one of the claims made by 
each of the named inventors. "Inventors may apply for a 
patent jointly even though 

(A)	they did not physically work together or at the 
same time, 

(B)	each did not make the same type or amount of 
contribution, or 

(C)	each did not make a contribution to the subject 
matter of every claim of the patent." 

35 U.S.C. 116. "[T]he statute neither states nor implies that 
two inventors can be `joint inventors' if they have had no 
contact whatsoever and are completely unaware of each 
other's work." What is required is some "quantum of col-
laboration or connection." In other words, "[f]or persons to 
be joint inventors under Section 116, there must be some 
element of joint behavior, such as collaboration or working 
under common direction, one inventor seeing a relevant 
report and building upon it or hearing another's suggestion 
at a meeting." Kimberly-Clark Corp. v. Procter & Gamble 
Distrib. Co., 973 F.2d 911, 916-17, 23 USPQ2d 1921, 
1925-26 (Fed. Cir. 1992); Moler v. Purdy, 131 USPQ 276, 
279 (Bd. Pat. Inter. 1960) ("it is not necessary that the 
inventive concept come to both [joint inventors] at the 
same time"). 

>Each joint inventor must generally contribute to the 
conception of the invention.  A coinventor need not make a 
contribution to every claim of a patent.  A contribution to 
one claim is enough. "The contributor of any disclosed 
means of a means-plus-function claim element is a joint 
inventor as to that claim, unless one asserting sole inventor-
ship can show that the contribution of that means was sim-
ply a reduction to practice of the sole inventor's broader 
concept." Ethicon Inc. v. United States Surgical Corp., 135 
F.3d 1456, 1460-63, 45 USPQ2d 1545, 1548-1551 (Fed. 
Cir. 1998)(The electronics technician who contributed to 
one of the two alternative structures in the specification to 
define "the means for detaining" in a claim limitation was 
held to be a joint inventor.).<

INVENTORSHIP IS GENERALLY "TO ANOTHER" 
WHERE THERE ARE DIFFERENT INVENTIVE 
ENTITIES WITH AT LEAST ONE INVENTOR IN 
COMMON

"[A] joint application or patent and a sole application or 
patent by one of the joint inventors are [by] different legal 
entities and accordingly, the issuance of the earlier filed 
application as a patent becomes a reference for everything 
it discloses" (Ex parte Utschig, 156 USPQ 156, 157 (Bd. 
App. 1966)) except where:

(A)	the claimed invention in a later filed application is 
entitled to the benefit of an earlier filed application under  
35 U.S.C. 120 (an overlap of inventors rather than an iden-
tical inventive entity is permissible). In this situation, a 
rejection under  35 U.S.C. 102(e) is precluded. See Applied 
Materials Inc. v. Gemini Research Corp., 835 F.2d 279, 
281, 15 USPQ2d 1816, 1818 (Fed. Cir. 1988) ("The fact 
that an application has named a different inventive entity 
than a patent does not necessarily make that patent prior 
art."); and 

(B)	the subject matter developed by another person 
and the claimed subject matter were, at the time the inven-
tion was made, owned by the same person or subject to an 
obligation of assignment to the same person. In this situa-
tion, a rejection under 35 U.S.C. 102(f)/103 or 102(g)/103 
is precluded by 35 U.S.C. 103(c).

For case law relating to inventorship by "another" 
involving different inventive entities with at least one 
inventor in common see Ex parte DesOrmeaux, 25 
USPQ2d 2040 (Bd. Pat. App. & Inter. 1992) (the presence 
of a common inventor in a reference patent and a pending 
application does not preclude the determination that the ref-
erence inventive entity is to "another" within the meaning 
of  35 U.S.C. 102(e)) and the discussion of prior art avail-
able under  35 U.S.C. 102(e) in  MPEP ? 2136.04.

2137.02	Applicability of 35 U.S.C. 103(c) 

35 U.S.C. 103(c) states that subsection (f) of  35 U.S.C. 
102 will not preclude patentability where subject matter 
developed by another person, that would otherwise qualify 
under  35 U.S.C. 102(f), and the claimed invention of an 
application under examination were owned by the same 
person or subject to an obligation of assignment to the same 
person at the time the invention was made. See MPEP 
? 706.02(l) and  ? 2146.

2138	35 U.S.C. 102(g)  [R-1]

35 U.S.C. 102.  Conditions for patentability; novelty and loss of 
right to patent.

A person shall be entitled to a patent unless -

*****

**>

(g)(1)	 during the course of an interference conducted under section 
135 or section 291, another inventor involved therein establishes, to the 
extent permitted in section 104, that before such person's invention 
thereof the invention was made by such other inventor and not abandoned, 
suppressed, or concealed, or (2) before such person's invention thereof, 
the invention was made in this country by another inventor who had not 
abandoned, suppressed, or concealed it. In determining priority of inven-
tion under this subsection, there shall be considered not only the respec-
tive dates of conception and reduction to practice of the invention, but also 
the reasonable diligence of one who was first to conceive and last to 
reduce to practice, from a time prior to conception by the other.<

35 U.S.C. 102(g) issues such as conception, reduction to 
practice and diligence, while more commonly applied to 
interference matters, also arise in other contexts. New Idea 
Farm Equip. Corp. v. Sperry Corp., 916 F.2d 1561, 1565, 
16 USPQ2d 1424, 1428 (Fed. Cir. 1990). For example, 
35 U.S.C. 102(g) and  35 U.S.C. 103 have been combined 
in the context of an ex parte rejection entirely divorced 
from the award of priority in an interference. In re Bass, 
474 F.2d 1276, 1283, 177 USPQ 178, 183 (CCPA 1973) (in 
an unsuccessful attempt to utilize a  37 CFR 1.131 affidavit 
relating to a combination application, applicants admitted 
that the subcombination screen of a copending application 
which issued as a patent was earlier conceived than the 
combination). See also E. I. Du Pont de Nemours & Co. v. 
Phillips Petroleum Co., 849 F.2d 1430, 1433-34, 7 
USPQ2d 1129, 1132 (Fed. Cir.), cert. denied, 488 U.S. 986 
(1988) (determining whether patent claims were novel 
under  35 U.S.C. 102(g) in an infringement proceeding); In 
re Costello, 717 F.2d 1346, 219 USPQ 389 (Fed. Cir. 1983) 
(discussing the concepts of conception and constructive 
reduction to practice in the context of a declaration under  
37 CFR 1.131); Kawai v. Metlesics, 480 F.2d 880, 178 
USPQ 158 (CCPA 1973) (holding constructive reduction to 
practice for priority under 35 U.S.C. 119 requires meeting 
the requirements of  35 U.S.C. 101 and 35 U.S.C. 112).

2138.01	Interference Practice 

35 U.S.C. 102(g) IS THE BASIS OF INTERFERENCE 
PRACTICE

Subsection (g) of  35 U.S.C. 102 is the basis of interfer-
ence practice for determining priority of invention between 
two parties. See   Bigham v. Godtfredsen, 857 F.2d 1415, 
1416, 8 USPQ2d 1266, 1267 (Fed. Cir. 1988), 35 U.S.C. 
135,  37 CFR 1.601+ and MPEP chapter 2300. An interfer-
ence is an inter partes proceeding directed at determining 
the first to invent as among the parties to the proceeding, 
involving two or more pending applications naming differ-
ent inventors or one or more pending applications and one 
or more unexpired patents naming different inventors 
(37 CFR 1.601(i)). The United States is unusual in having a 
first to invent rather than a first to file system. Paulik v. Riz-
kalla, 760 F.2d 1270, 1272, 226 USPQ 224, 225 (Fed. Cir. 
1985) (reviews the legislative history of the subsection in a 
concurring opinion by Judge Rich). The first of many to 
reduce an invention to practice around the same time will 
be the sole party to obtain a patent, Radio Corp. of America 
v. Radio Eng'g Labs., Inc., 293 U.S. 1,2, 21 USPQ 353, 
353-4 (1934), unless another was the first to conceive and 
couple a later-in-time reduction to practice with diligence 
from a time just prior to when the second conceiver entered 
the field to the first conceiver's reduction to practice. Hull 
v. Davenport, 90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 
1937). See the priority time charts below illustrating this 
point. Upon conclusion of an interference, subject matter 
claimed by the losing party that was the basis of the inter-
ference is rejected under 35 U.S.C. 102(g), unless the acts 
showing prior invention were not in this country.

It is noted that 35 U.S.C. 101 requires that whoever 
invents or discovers is the party who may obtain a patent 
for the particular invention or discovery.  35 U.S.C. 111 
(applicant) or 35 U.S.C. 116 (applicants) set forth the 
requirement that the actual inventor(s) be the party who 
applies for a patent or that a patent be applied for on behalf 
of the inventor. Where it can be shown that an applicant has 
"derived" an invention from another, a rejection under 
35 U.S.C. 102(f) is proper. Ex parte Kusko, 215 USPQ 972, 
974 (Bd. App. 1981) ("most, if not all, determinations 
under Section 102(f) involve the question of whether one 
party derived an invention from another"); Price v. Symsek, 
988 F.2d 1187, 1190, 26 USPQ2d 1031, 1033 (Fed. Cir. 
1993)(Although derivation and priority of invention both 
focus on inventorship, derivation addresses originality, i.e., 
who invented the subject matter, whereas priority focuses 
on which party invented the subject matter first.). 

PRIORITY TIME CHARTS

The following priority time charts illustrate the award of 
invention priority in several situations. The time charts 
apply to interference proceedings and are also applicable to 
declarations or affidavits filed under 37 CFR 1.131 to ante-
date references which are available as prior art under 
35 U.S.C. 102(a) or 102(e). Note, however, in the context 
of  37 CFR 1.131, an applicant does not have to show that 
the invention was not abandoned, suppressed, or concealed 
from the time of an actual reduction to practice to a con-
structive reduction to practice because the length of time 
taken to file a patent application after an actual reduction to 
practice is generally of no consequence except in an inter-
ference proceeding. Paulik v. Rizkalla, 760 F.2d 1270, 226 
USPQ 224 (Fed. Cir. 1985). See the discussion of abandon-
ment, suppression, and concealment in  MPEP ? 2138.03.

For purposes of analysis under 37 CFR 1.131, the con-
ception and reduction to practice of the reference to be 
antedated are both considered to be on the effective filing 
date of domestic patent or foreign patent or the date of 
printed publication.

In the charts, C = conception, R = reduction to practice 
(either actual or constructive), Ra = actual reduction to 
practice, Rc = constructive reduction to practice, and TD = 
commencement of diligence.

Example 1

A is awarded priority in an interference, or antedates B 
as a reference in the context of a declaration or affidavit 
filed under  37 CFR 1.131, because A conceived the 
invention before B and constructively reduced the 
invention to practice before B reduced the invention to 
practice. The same result would be reached if the con-
ception date was the same for both inventors A and B. 

Example 2

A is awarded priority in an interference, or antedates B 
as a reference in the context of a declaration or affidavit 
filed under  37 CFR 1.131, if A can show reasonable 
diligence from TD (a point just prior to B's conception) 
until Rc because A conceived the invention before B, 
and diligently constructively reduced the invention to 
practice even though this was after B reduced the inven-
tion to practice.

Example 3

A is awarded priority in an interference in the absence 
of abandonment, suppression, or concealment from Ra 
to Rc, because A conceived the invention before B, 
actually reduced the invention to practice before B 
reduced the invention to practice, and did not abandon, 
suppress, or conceal the invention after actually reduc-
ing the invention to practice and before constructively 
reducing the invention to practice.

A antedates B as a reference in the context of a declara-
tion or affidavit filed under 37 CFR 1.131 because A 
conceived the invention before B and actually reduced 
the invention to practice before B reduced the invention 
to practice.

Example 4

A is awarded priority in an interference if A can show 
reasonable diligence from TD (a point just prior to B's 
conception) until Ra in the absence of abandonment, 
suppression, or concealment from Ra to Rc, because A 
conceived the invention before B, diligently actually 
reduced the invention to practice (after B reduced the 
invention to practice), and did not abandon, suppress, or 
conceal the invention after actually reducing the inven-
tion to practice and before constructively reducing the 
invention to practice.

A antedates B as a reference in the context of a declara-
tion or affidavit filed under 37 CFR 1.131 because A 
conceived the invention before B, and diligently actu-
ally reduced the invention to practice, even though this 
was after B reduced the invention to practice.

37 CFR 1.131 DOES NOT APPLY IN 
INTERFERENCE PROCEEDINGS

Interference practice operates to the exclusion of ex 
parte practice under  37 CFR 1.131 which permits an appli-
cant to show an actual date of invention prior to the effec-
tive date of a patent or literature reference applied under 
35 U.S.C. 102(a) or (e), as long as the patent is not a 
domestic patent claiming the same patentable invention. Ex 
parte Standish, 10 USPQ2d 1454, 1457 (Bd. Pat. App. & 
Inter. 1988) (An application claim to the "same patentable 
invention" claimed in a domestic patent requires interfer-
ence rather than an affidavit under 37 CFR 1.131 to ante-
date the patent. The term "same patentable invention" 
encompasses a claim that is either anticipated by or obvious 
in view of the subject matter recited in the patent claim.). 
Subject matter which is available as prior art only under 
35 U.S.C. 102(g) is by definition made before the applicant 
made his invention and is therefore not open to further 
inquiry under  37 CFR 1.131.

LOST COUNTS IN AN INTERFERENCE ARE NOT, 
PER SE, STATUTORY PRIOR ART

Loss of an interference count alone does not make its 
subject matter statutory prior art to losing party; however, 
lost count subject matter that is available as prior art under  
35 U.S.C. 102 may be used alone or in combination with 
other references under  35 U.S.C. 103. But see In re Deck-
ler, 977 F.2d 1449, 24 USPQ2d 1448 (Fed. Cir. 1992) 
(Under the principles of res judicata and   collateral estop-
pel, Deckler was not entitled to claims that were patentably 
indistinguishable from the claim lost in interference even 
though the subject matter of the lost count was not avail-
able for use in an obviousness rejection under 35 U.S.C. 
103.).

2138.02	"The Invention Was Made in This 
Country"  [R-1]

An invention is made when there is a conception and a 
reduction to practice. Dunn v. Ragin, 50 USPQ 472, 474 
(Bd. Pat. Inter. 1941). Prior art under  35 U.S.C. 102(g) is 
limited to an invention that is made. In re Katz, 687 F.2d 
450, 454, 215 USPQ 14, 17 (CCPA 1982) (the publication 
of an article, alone, is not deemed a constructive reduction 
to practice, and therefore its disclosure does not prove that 
any invention within the meaning of 35 U.S.C. 102(g) has 
ever been made). 

Subject matter under 35 U.S.C. 102(g) is available only 
if made in this country.  35 U.S.C. 104. Kondo v. Martel, 
220 USPQ 47 (Bd. Pat. Inter. 1983) (acts of conception, 
reduction to practice and diligence must be demonstrated in 
this country). Compare Colbert v. Lofdahl, 21 USPQ2d 
1068, 1071 (Bd. Pat. App. & Inter. 1991) ("[i]f the inven-
tion is reduced to practice in a foreign country and knowl-
edge of the invention was brought into this country and 
disclosed to others, the inventor can derive no benefit from 
the work done abroad and such knowledge is merely evi-
dence of conception of the invention").

** >In accordance with 35 U.S.C.  102(g)(1), a party 
involved in an interference proceeding under 35 U.S.C.  
135 or  291 may establish a date of invention under 
35 U.S.C.  104.<  35 U.S.C. 104, as amended by GATT 
(Public Law 103-465, 108 Stat. 4809 (1994)) and NAFTA 
(Public Law 103-182, 107 Stat. 2057 (1993)), provides that 
an applicant can establish a date of invention in a NAFTA 
member country on or after December 8, 1993 or in WTO 
member country other than a NAFTA member country on 
or after January 1, 1996. Accordingly, an interference count 
may be won or lost on the basis of establishment of inven-
tion by one of the parties in a NAFTA or WTO member 
country, thereby rendering the subject matter of that count 
unpatentable to the other party under the principles of res 
judicata and collateral estoppel, even though such subject 
matter is not available as statutory prior art under 35 U.S.C. 
102(g). See  MPEP ? 2138.01 regarding lost interference 
counts which are not statutory prior art. 

2138.03	"By Another Who Has Not 
Abandoned, Suppressed, or  
Concealed It" 

35 U.S.C. 102(g) generally makes available as prior art 
within the meaning of  35 U.S.C. 103, the prior invention of 
another who has not abandoned, suppressed or concealed it. 
In re Bass, 474 F.2d 1276, 177 USPQ 178 (CCPA 1973);  
In re Suska, 589 F.2d 527, 200 USPQ 497 (CCPA 1979) 
(The result of applying the suppression and concealment 
doctrine is that the inventor who did not conceal (but was 
the de facto last inventor) is treated legally as the first to 
invent, while the de facto first inventor who suppressed or 
concealed is treated as a later inventor. The de facto first 
inventor, by his suppression and concealment, lost the right 
to rely on his actual date of invention not only for priority 
purposes, but also for purposes of avoiding the invention of 
the counts as prior art.).

"The courts have consistently held that an invention, 
though completed, is deemed abandoned, suppressed, or 
concealed if, within a reasonable time after completion, no 
steps are taken to make the invention publicly known. Thus 
failure to file a patent application; to describe the invention 
in a publicly disseminated document; or to use the inven-
tion publicly, have been held to constitute abandonment, 
suppression, or concealment." Correge v. Murphy, 705 F.2d 
1326, 1330,   217 USPQ 753, 756 (Fed. Cir. 1983) (quoting 
International Glass Co. v. United States, 408 F.2d 395, 403, 
159 USPQ 434, 441 (Ct. Cl. 1968)). In Correge, an inven-
tion was actually reduced to practice, 7 months later there 
was a public disclosure of the invention, and 8 months 
thereafter a patent application was filed. The court held fil-
ing a patent application within 1 year of a public disclosure 
is not an unreasonable delay, therefore reasonable diligence 
must only be shown between the date of the actual reduc-
tion to practice and the public disclosure to avoid the infer-
ence of abandonment.

DURING AN INTERFERENCE PROCEEDING, AN 
INFERENCE OF SUPPRESSION OR CONCEAL-
MENT MAY ARISE FROM DELAY IN FILING 
PATENT APPLICATION

Once an invention is actually reduced to practice an 
inventor need not rush to file a patent application. Shin-
delar v. Holdeman, 628 F.2d 1337, 1341, 207 USPQ 112, 
116 (CCPA 1980). The length of time taken to file a patent 
application after an actual reduction to practice is generally 
of no consequence except in an interference proceeding. 
Paulik v. Rizkalla, 760 F.2d 1270, 1271, 226 USPQ 225, 
226 (Fed. Cir. 1985) (suppression or concealment may be 
deliberate or may arise due to an inference from a "too 
long" delay in filing a patent application). Peeler v. Miller, 
535 F.2d 647, 656, 190 USPQ 117,124 (CCPA 1976) 
("mere delay, without more, is not sufficient to establish 
suppression or concealment." "What we are deciding here 
is that Monsanto's delay is not `merely delay' and that 
Monsanto's justification for the delay is inadequate to over-
come the inference of suppression created by the excessive 
delay." The word "mere" does not imply a total absence of 
a limit on the duration of delay. Whether any delay is 
"mere" is decided only on a case-by-case basis.).

Where a junior party in an interference relies upon an 
actual reduction to practice to demonstrate first inventor-
ship, and where the hiatus in time between the date for the 
junior party's asserted reduction to practice and the filing of 
its application is unreasonably long, the hiatus may give 
rise to an inference that the junior party in fact suppressed 
or concealed the invention and the junior party will not be 
allowed to rely upon the earlier actual reduction to practice. 
Young v. Dworkin, 489 F.2d 1277, 1280 n.3, 180 USPQ 
388, 391 n.3 (CCPA 1974) (suppression and concealment 
issues are to be addressed on a case-by-case basis). 

SUPPRESSION OR CONCEALMENT NEED NOT 
BE ATTRIBUTED TO INVENTOR

Suppression or concealment need not be attributed to the 
inventor. Peeler v. Miller, 535 F.2d 647, 653-54, 190 USPQ 
117, 122 (CCPA 1976) ("four year delay from the time an 
inventor ? completes his work ? and the time his 
assignee-employer files a patent application is, prima facie, 
unreasonably long in an interference with a party who filed 
first");   Shindelar v. Holdeman, 628 F.2d 1337, 1341-42, 
207 USPQ 112, 116-17 (CCPA 1980) (A patent attorney's 
workload will not preclude a holding of an unreasonable 
delay-a total of 3 months was identified as possible of 
excuse in regard to the filing of an application.).

INFERENCE OF SUPPRESSION OR CONCEAL-
MENT IS REBUTTABLE

Notwithstanding a finding of suppression or conceal-
ment, a constructive reduction to practice such as renewed 
activity just prior to other party's entry into field coupled 
with the diligent filing of an application would still cause 
the junior party to prevail. Lutzker v. Plet, 843 F.2d 1364, 
1367-69, 6 USPQ2d 1370, 1371-72 (Fed. Cir. 1988) (activ-
ities directed towards commercialization not sufficient to 
rebut inference); Holmwood v. Cherpeck, 2 USPQ2d 1942, 
1945 (Bd. Pat. App. & Inter. 1986) (the inference of sup-
pression or concealment may be rebutted by showing activ-
ity directed to perfecting the invention, preparing the 
application, or preparing other compounds within the scope 
of the generic invention); Engelhardt v. Judd, 369 F.2d 408, 
411, 151 USPQ 732, 735 (CCPA 1966) ("We recognize that 
an inventor of a new series of compounds should not be 
forced to file applications piecemeal on each new member 
as it is synthesized, identified and tested for utility. A rea-
sonable amount of time should be allowed for completion 
of the research project on the whole series of new com-
pounds, and a further reasonable time period should then be 
allowed for drafting and filing the patent application(s) 
thereon."); Bogoslowsky v. Huse, 142 F.2d 75, 77, 61 USPQ 
349, 351 (CCPA 1944) (The doctrine of suppression and 
concealment is not applicable to conception without an 
actual reduction to practice.).

ABANDONMENT

A finding of suppression or concealment may not 
amount to a finding of abandonment wherein a right to a 
patent is lost. Steierman v. Connelly, 197 USPQ 288, 289 
(Comm'r Pat. 1976); Correge v. Murphy, 705 F.2d 1326, 
1329, 217 USPQ 753, 755 (Fed. Cir. 1983) (an invention 
cannot be abandoned until it is first reduced to practice). 

2138.04	"Conception" 

Conception has been defined as "the complete perfor-
mance of the mental part of the inventive act" and it is "the 
formation in the mind of the inventor of a definite and per-
manent idea of the complete and operative invention as it is 
thereafter to be applied in practice?." Townsend v. Smith, 
36 F.2d 292, 295, 4 USPQ 269, 271 (CCPA 1930). 
"[C]onception is established when the invention is made 
sufficiently clear to enable one skilled in the art to reduce it 
to practice without the exercise of extensive experimenta-
tion or the exercise of inventive skill." Hiatt v. Ziegler, 179 
USPQ 757, 763 (Bd. Pat. Inter. 1973). Conception has also 
been defined as a disclosure of an invention which enables 
one skilled in the art to reduce the invention to a practical 
form without "exercise of the inventive faculty." Gunter v. 
Stream, 573 F.2d 77, 197 USPQ 482 (CCPA 1978). See 
also Coleman v. Dines, 754 F.2d 353, 224 USPQ 857 (Fed. 
Cir. 1985) (It is settled that in establishing conception a 
party must show possession of every feature recited in the 
count, and that every limitation of the count must have 
been known to the inventor at the time of the alleged con-
ception. Conception must be proved by corroborating evi-
dence.); Hybritech Inc. v. Monoclonal Antibodies Inc., 802 
F. 2d 1367, 1376, 231 USPQ 81, 87 (Fed. Cir. 1986) (Con-
ception is the "formation in the mind of the inventor, of a 
definite and permanent idea of the complete and operative 
invention, as it is hereafter to be applied in practice.").

CONCEPTION MUST BE DONE IN THE MIND OF 
THE INVENTOR 

The inventor must form a definite and permanent idea of 
the complete and operable invention to establish concep-
tion. Bosies v. Benedict, 27 F.3d 539, 543, 30 USPQ2d 
1862, 1865 (Fed. Cir. 1994) (Testimony by a noninventor 
as to the meaning of a variable of a generic compound 
described in an inventor's notebook was insufficient as a 
matter of law to establish the meaning of the variable 
because the testimony was not probative of what the inven-
tors conceived.).

AS LONG AS THE INVENTOR MAINTAINS INTEL-
LECTUAL DOMINATION OVER MAKING THE 
INVENTION, IDEAS, SUGGESTIONS, AND MATE-
RIALS MAY BE ADOPTED FROM OTHERS 

An inventor may consider and adopt ideas, suggestions 
and materials derived from many sources: a suggestion 
from an employee, a hired consultant or a friend even if the 
adopted material proves to be the key that unlocks the prob-
lem so long as the inventor "maintains intellectual domina-
tion of the work of making the invention down to the 
successful testing, selecting or rejecting?." Morse v. Por-
ter, 155 USPQ 280, 283 (Bd. Pat. Inter. 1965); Staehelin v. 
Secher, 24 USPQ2d 1513, 1522 (Bd. Pat. App. & Inter. 
1992) ("evidence of conception naming only one of the 
actual inventive entity inures to the benefit of and serves as 
evidence of conception by the complete inventive entity").

CONCEPTION REQUIRES CONTEMPORANEOUS 
RECOGNITION AND APPRECIATION OF THE 
INVENTION

There must be a contemporaneous recognition and 
appreciation of the invention for there to be conception. Sil-
vestri v. Grant, 496 F.2d 593, 596, 181 USPQ 706, 708 
(CCPA 1974) ("an accidental and unappreciated duplica-
tion of an invention does not defeat the patent right of one 
who, though later in time was the first to recognize that 
which constitutes the inventive subject matter"); Langer v. 
Kaufman, 465 F.2d  915, 918, 175 USPQ 172, 174 (CCPA 
1972) (new form of catalyst was not recognized when it 
was first produced; conception cannot be established nunc 
pro tunc). However, an inventor does not need to know that 
the invention will work for there to be complete concep-
tion. Burroughs Wellcome Co. v. Barr Labs., Inc., 40 F.3d 
1223, 1228, 32 USPQ2d 1915, 1919 (Fed. Cir. 1994) (Draft 
patent application disclosing treatment of AIDS with AZT 
reciting dosages, forms, and routes of administration was 
sufficient to collaborate conception whether or not the 
inventors believed the inventions would work based on ini-
tial screening tests.).

While conception of a species within a genus may con-
stitute conception of the genus, conception of one species 
and the genus may not constitute conception of another 
species in the genus. Oka v. Youssefyeh, 849 F.2d 581, 7 
USPQ2d 1169 (Fed. Cir. 1988) (conception of a chemical 
requires both the idea of the structure of the chemical and 
possession of an operative method of making it). See also 
Amgen v. Chugai Pharmaceutical Co., 927 F.2d 1200, 
1206, 18 USPQ2d 1016, 1021 (Fed. Cir. 1991) (in the isola-
tion of a gene, defining a gene by its principal biological 
property is not sufficient for conception absent an ability to 
envision the detailed constitution as well as a method for 
obtaining it); Fiers v. Revel, 984 F.2d 1164, 1170, 25 
USPQ2d 1601, 1605 (Fed. Cir. 1993) ("[b]efore reduction 
to practice, conception only of a process for making a sub-
stance, without conception of a structural or equivalent def-
inition of that substance, can at most constitute a 
conception of the substance claimed as a process" but can-
not constitute conception of the substance; as "conception 
is not enablement," conception of a purified DNA sequence 
coding for a specific protein by function and a method for 
its isolation that could be carried out by one of ordinary 
skill in the art is not conception of that material).

On rare occasions conception and reduction to practice 
occur simultaneously. Alpert v. Slatin, 305 F.2d 891, 894, 
134 USPQ 296, 299 (CCPA 1962). "[I]n some unpredict-
able areas of chemistry and biology, there is no conception 
until the invention has been reduced to practice." Mac-
Millan v. Moffett, 432 F.2d 1237, 1234-40, 167 USPQ 550, 
552-553 (CCPA 1970). See also Dunn v. Ragin, 50 USPQ 
472, 475 (Bd. Pat. Inter. 1941) (a new variety of asexually 
reproduced plant is conceived and reduced to practice when 
it is grown and recognized as a new variety). Under these 
circumstances, conception is not complete if subsequent 
experimentation reveals factual uncertainty which "so 
undermines the specificity of the inventor's idea that it is 
not yet a definite and permanent reflection of the complete 
invention as it will be used in practice." Burroughs 
Wellcome Co. v. Barr Labs., Inc., 40 F.3d 1223, 1229, 32 
USPQ2d 1915, 1920 (Fed. Cir. 1994).

A PREVIOUSLY ABANDONED APPLICATION 
WHICH WAS NOT COPENDING WITH A SUBSE-
QUENT APPLICATION IS EVIDENCE ONLY OF 
CONCEPTION

An abandoned application with which no subsequent 
application was copending serves to abandon benefit of the 
application's filing as a constructive reduction to practice 
and the abandoned application is evidence only of concep-
tion. In re Costello, 717 F.2d 1346, 1350, 219 USPQ 389, 
392 (Fed. Cir. 1983).

2138.05	"Reduction to Practice"  [R-1]

**>Reduction to practice may be an actual reduction or 
a constructive reduction to practice which occurs when a 
patent application on the claimed invention is filed. The fil-
ing of a patent application serves as conception and con-
structive reduction to practice of the subject matter 
described in the application. Thus the inventor need not 
provide evidence of either conception or actual reduction to 
practice when relying on the content of the patent applica-
tion. Hyatt v. Boone, 146 F.3d 1348, 1352, 47 USPQ2d 
1128, 1130 (Fed. Cir. 1998).<  A reduction to practice can 
be done by another on behalf of the inventor. De Solms v. 
Schoenwald, 15 USPQ2d 1507, 1510 (Bd. Pat. App. & 
Inter. 1990). "While the filing of the original application 
theoretically constituted a constructive reduction to prac-
tice at the time, the subsequent abandonment of that appli-
cation also resulted in an abandonment of the benefit of that 
filing as a constructive reduction to practice. The filing of 
the original application is, however, evidence of conception 
of the invention." In re Costello, 717 F.2d 1346, 1350, 219 
USPQ 389, 392 (Fed. Cir. 1983).

CONSTRUCTIVE REDUCTION TO PRACTICE 
REQUIRES COMPLIANCE WITH 35 U.S.C. 112, 
FIRST PARAGRAPH

>When a party to an interference seeks the benefit of an 
earlier-filed U.S. patent application, the earlier application 
must meet the requirements of 35 U.S.C. 120 and 35 U.S.C.  
112, first paragraph for the subject matter of the count. The 
earlier application must meet the enablement requirement 
and must contain a written description of the subject matter 
of the interference count.  Hyatt v. Boone, 146 F.3d 1348, 
1352, 47 USPQ2d 1128, 1130 (Fed. Cir. 1998).<  Proof of a 
constructive reduction to practice requires sufficient disclo-
sure under the "how to use" and "how to make" require-
ments of 35 U.S.C. 112, first paragraph. Kawai v. Metlesics, 
480 F.2d 880, 886, 178 USPQ 158, 163 (CCPA 1973) (A 
constructive reduction to practice is not proven unless the 
specification discloses a practical utility where one would 
not be obvious. Prior art which disclosed an anticonvulsant 
compound which differed from the claimed compound only 
in the absence of a -CH2- group connecting two functional 
groups was not sufficient to establish utility of the claimed 
compound because the compounds were not so closely 
related that they could be presumed to have the same util-
ity.).  >The purpose of the written description requirement 
is "to ensure that the inventor had possession, as of the fil-
ing date of the application relied on, of the specific subject 
matter later claimed by him." In re Edwards, 568 F.2d 
1349, 1351-52, 196 USPQ 465, 467 (CCPA 1978). The 
written description must include all of the limitations of the 
interference count, or the applicant must show that any 
absent text is necessarily comprehended in the description 
provided and would have been so understood at the time 
the patent application was filed. Furthermore, the written 
description must be sufficient, when the entire specification 
is considered, such that the "necessary and only reasonable 
construction" that would be given it by a person skilled in 
the art is one that clearly supports each positive limitation 
in the count. Hyatt v. Boone, 146 F.3d at 1354-55, 47 
USPQ2d at 1130-1132 (Fed. Cir. 1998)(The claim could be 
read as describing subject matter other than that of the 
count and thus did not establish that the applicant was in 
possession of the invention of the count.).<  See also Big-
ham v. Godtfredsen, 857 F.2d 1415, 1417, 8 USPQ2d 1266, 
1268 (Fed. Cir. 1988) ("[t]he generic term halogen compre-
hends a limited number of species, and ordinarily consti-
tutes a sufficient written description of the common 
halogen species," except where the halogen species are pat-
entably distinct). 

**

REQUIREMENTS TO ESTABLISH ACTUAL 
REDUCTION TO PRACTICE

 >"In an interference proceeding, a party seeking to 
establish an actual reduction to practice must satisfy a two-
prong test: (1) the party constructed an embodiment or per-
formed a process that met every element of the interference 
count, and (2) the embodiment or process operated for its 
intended purpose." Eaton v. Evans, Fed. Cir., No. 99-1267, 
2000 U.S. App. LEXIS 1250 (2/2/00).<

The same evidence sufficient for a constructive reduc-
tion to practice may be insufficient to establish an actual 
reduction to practice, which requires a showing of the 
invention in a physical or tangible form that shows every 
element of the count. Wetmore v. Quick, 536 F.2d 937, 942, 
190 USPQ 223, 227 (CCPA 1976). For an actual reduction 
to practice, the invention must have been sufficiently tested 
to demonstrate that it will work for its intended purpose, 
but it need not be in a commercially satisfactory stage of 
development. If a device is so simple, and its purpose and 
efficacy so obvious, construction alone is sufficient to dem-
onstrate workability. King Instrument Corp. v. Otari Corp., 
767 F.2d 853, 860, 226 USPQ 402, 407 (Fed. Cir. 1985).

For additional cases pertaining to the requirements nec-
essary to establish actual reduction to practice see DSL 
Dynamic Sciences, Ltd. v. Union Switch & Signal, Inc., 928 
F.2d 1122, 1126, 18 USPQ2d 1152, 1155 (Fed. Cir. 1991) 
("events occurring after an alleged actual reduction to prac-
tice can call into question whether reduction to practice has 
in fact occurred"); Corona v. Dovan, 273 U.S. 692, 1928 
C.D. 252 (1928) ("A process is reduced to practice when it 
is successfully performed. A machine is reduced to practice 
when it is assembled, adjusted and used. A manufacture 
[i.e., article of manufacture] is reduced to practice when it 
is completely manufactured. A composition of matter is 
reduced to practice when it is completely composed." 1928 
C.D. at 262-263 (emphasis added).); Fitzgerald v. Arbib, 
268 F.2d 763, 765-66, 122 USPQ 530, 531-32 (CCPA 
1959) ("the reduction to practice of a three-dimensional 
design invention requires the production of an article 
embodying that design" in "other than a mere drawing"). 

TESTING REQUIRED TO ESTABLISH AN ACTUAL 
REDUCTION TO PRACTICE

"The nature of testing which is required to establish a 
reduction to practice depends on the particular facts of each 
case, especially the nature of the invention." Gellert v. Wan-
berg, 495 F.2d 779, 783, 181 USPQ 648, 652 (CCPA 1974) 
("an invention may be tested sufficiently ? where less than 
all of the conditions of actual use are duplicated by the 
tests"); Wells v. Fremont, 177 USPQ 22, 24-5 (Bd. Pat. 
Inter. 1972) ("even where tests are conducted under `bench' 
or laboratory conditions, those conditions must `fully dupli-
cate each and every condition of actual use' or if they do 
not, then the evidence must establish a relationship between 
the subject matter, the test condition and the intended func-
tional setting of the invention," but it is not required that all 
the conditions of all actual uses be duplicated, such as rain, 
snow, mud, dust and submersion in water). 

REDUCTION TO PRACTICE REQUIRES RECOG-
NITION AND APPRECIATION OF THE INVEN-
TION

The invention must be recognized and appreciated for a 
reduction to practice to occur. Alsenz v. Hargraves, 13 
USPQ2d 1371, 1374 (Bd. Pat. App. & Int. 1989) (a reduc-
tion to practice cannot be established nunc pro tunc); 
Meitzner v. Corte, 537 F.2d 524, 528, 190 USPQ 407, 410 
(CCPA 1976) (there can be no conception or reduction to 
practice of a new form or of a process using such a new 
form of an otherwise old composition where there has been 
no recognition or appreciation of the existence of the new 
form);   Estee Lauder, Inc. v. L'Oreal S.A., 129 F.3d 588, 
593, 44 USPQ2d 1610, 1615 (Fed. Cir. 1997) ("[W]hen 
testing is necessary to establish utility, there must be recog-
nition and appreciation that the tests were successful for 
reduction to practice to occur."  A showing that testing was 
completed before the critical date, and that testing ulti-
mately proved successful, was held insufficient to establish 
a reduction to practice before the critical date, since the 
success of the testing was not appreciated or recognized 
until after the critical date.); Parker v. Frilette, 462 F.2d 
544, 547, 174 USPQ 321, 324 (CCPA 1972) ("[an] inventor 
need not understand precisely why his invention works in 
order to achieve an actual reduction to practice"). 

IN AN INTERFERENCE PROCEEDING, ALL 
LIMITATIONS OF A COUNT MUST BE REDUCED 
TO PRACTICE

The device reduced to practice must include every limi-
tation of the count. Fredkin v. Irasek, 397 F.2d 342, 158 
USPQ 280, 285 (CCPA 1968); every limitation in a count is 
material and must be proved to establish an actual reduc-
tion to practice.   Meitzner v. Corte, 537 F.2d 524, 528, 190 
USPQ 407, 410. See also Hull v. Bonis, 214 USPQ 731, 
734 (Bd. Pat. Inter. 1982) (no doctrine of equivalents-
remedy is a preliminary motion to amend the count to con-
form to the proofs). 

CLAIMED INVENTION IS NOT ACTUALLY 
REDUCED TO PRACTICE UNLESS THERE IS A 
KNOWN UTILITY

Utility for the invention must be known at the time of the 
reduction to practice. Wiesner v. Weigert, 666 F.2d 582, 
588, 212 USPQ 721, 726 (CCPA 1981) (except for plant 
and design inventions); Azar v. Burns, 188 USPQ 601, 604 
(Bd. Pat. Inter. 1975) (a composition and a method cannot 
be actually reduced to practice unless the composition and 
the product produced by the method have a practical util-
ity);   Ciric v. Flanigen, 511 F.2d 1182, 1185, 185 USPQ 
103, 105-6 (CCPA 1975) ("when a count does not recite 
any particular utility, evidence establishing a substantial 
utility for any purpose is sufficient to prove a reduction to 
practice"; "the demonstrated similarity of ion exchange and 
adsorptive properties between the newly discovered zeo-
lites and known crystalline zeolites ? have established  
utility for the zeolites of the count"); Engelhardt v. Judd, 
369 F.2d 408, 411, 151 USPQ 732, 735 (CCPA 1966) 
(When considering an actual reduction to practice as a bar 
to patentability for claims to compounds, it is sufficient to 
successfully demonstrate utility of the compounds in ani-
mals for somewhat different pharmaceutical purposes than 
those asserted in the specification for humans.); Rey-Bellet 
v. Engelhardt, 993 F.2d 1380, 1384, 181 USPQ 453, 455 
(CCPA 1974) (Two categories of tests on laboratory ani-
mals have been considered adequate to show utility and 
reduction to practice: first, tests carried out to prove utility 
in humans where there is a satisfactory correlation between 
humans and animals, and second, tests carried out to prove 
utility for treating animals.).

A PROBABLE UTILITY MAY NOT BE SUFFICIENT 
TO ESTABLISH UTILITY

A probable utility does not establish a practical utility, 
which is established by actual testing or where the utility 
can be "foretold with certainty." Bindra v. Kelly, 206 USPQ 
570, 575 (Bd. Pat. Inter. 1979) (Reduction to practice was 
not established for an intermediate useful in the preparation 
of a second intermediate with a known utility in the prepa-
ration of a pharmaceutical. The record established there 
was a high degree of probability of a successful preparation 
because one skilled in the art may have been motivated, in 
the sense of  35 U.S.C. 103, to prepare the second interme-
diate from the first intermediate. However, a strong proba-
bility of utility is not sufficient to establish practical 
utility.); Wu v. Jucker, 167 USPQ 467, 472 (Bd. Pat. Inter. 
1968) (screening test where there was an indication of pos-
sible utility is insufficient to establish practical utility). But 
see Nelson v. Bowler, 628 F.2d 853, 858, 206 USPQ 881, 
885 (CCPA 1980) (Relevant evidence is judged as a whole 
for its persuasiveness in linking observed properties to sug-
gested uses. Reasonable correlation between the two is suf-
ficient for an actual reduction to practice.).

2138.06	"Reasonable Diligence" 

The diligence of  35 U.S.C. 102(g) relates to rea sonable 
"attorney-diligence" and "engineering-diligence" (Keizer v. 
Bradley, 270 F.2d 396, 397, 123 USPQ 215, 216 (CCPA 
1959)), which does not require that "an inventor or his 
attorney ? drop all other work and concentrate on the par-
ticular invention involved?." Emery v. Ronden, 188 USPQ 
264, 268 (Bd. Pat. Inter. 1974). 

CRITICAL PERIOD FOR ESTABLISHING DILI-
GENCE BETWEEN ONE WHO WAS FIRST TO 
CONCEIVE BUT LATER TO REDUCE TO PRAC-
TICE THE INVENTION

The critical period for diligence for a first conceiver but 
second reducer begins not at the time of conception of the 
first conceiver but just prior to the entry in the field of the 
party who was first to reduce to practice and continues until 
the first conceiver reduces to practice. Hull v. Davenport, 
90 F.2d 103, 105, 33 USPQ 506, 508 (CCPA 1937) ("lack 
of diligence from the time of conception to the time imme-
diately preceding the conception date of the second con-
ceiver is not regarded as of importance except as it may 
have a bearing upon his subsequent acts"). What serves as 
the entry date into the field of a first reducer is dependent 
upon what is being relied on by the first reducer, e.g., con-
ception plus reasonable diligence to reduction to practice 
(Fritsch v. Lin, 21 USPQ2d 1731, 1734 (Bd. Pat. App. & 
Inter. 1991), Emery v. Ronden, 188 USPQ 264, 268 (Bd. 
Pat. Inter. 1974)); an actual reduction to practice or a con-
structive reduction to practice by the filing of either a U.S. 
application (Rebstock v. Flouret, 191 USPQ 342, 345 (Bd. 
Pat. Inter. 1975)) or reliance upon priority under 35 U.S.C. 
119 of a foreign application (Justus v. Appenzeller, 177 
USPQ 332, 339 (Bd. Pat. Inter. 1971) (chain of priorities 
under 35 U.S.C. 119 and 120, priority under 35 U.S.C. 119 
denied for failure to supply certified copy of the foreign 
application during pendency of the application filed within 
the twelfth month)). 

THE ENTIRE PERIOD DURING WHICH DILI-
GENCE IS REQUIRED MUST BE ACCOUNTED 
FOR BY EITHER AFFIRMATIVE ACTS OR 
ACCEPTABLE EXCUSES

An applicant must account for the entire period during 
which diligence is required. Gould v. Schawlow, 363 F.2d 
908, 919, 150 USPQ 634, 643 (CCPA 1966) (Merely stat-
ing that there were no weeks or months that the invention 
was not worked on is not enough.); In re Harry, 333 F.2d 
920, 923, 142 USPQ 164, 166 (CCPA 1964) (statement that 
the subject matter "was diligently reduced to practice" is 
not a showing but a mere pleading). A 2-day period lacking 
activity has been held to be fatal. In re Mulder, 716 F.2d 
1542, 1545, 219 USPQ 189, 193  (Fed. Cir. 1983) (37 CFR 
1.131 issue); Fitzgerald v. Arbib, 268 F.2d 763, 766, 122 
USPQ 530, 532 (CCPA 1959) (Less than 1 month of inac-
tivity during critical period. Efforts to exploit an invention 
commercially do not constitute diligence in reducing it to 
practice. An actual reduction to practice in the case of a 
design for a three-dimensional article requires that it should 
be embodied in some structure other than a mere drawing.); 
Kendall v. Searles, 173 F.2d 986, 993, 81 USPQ 363, 369 
(CCPA 1949) (Diligence requires that applicants must be 
specific as to dates and facts.). 

The period during which diligence is required must be 
accounted for by either affirmative acts or acceptable 
excuses. Rebstock v. Flouret, 191 USPQ 342, 345 (Bd. Pat. 
Inter. 1975); Rieser v. Williams, 225 F.2d 419, 423, 118 
USPQ 96, 100 (CCPA 1958) (Being last to reduce to prac-
tice, party cannot prevail unless he has shown that he was 
first to conceive and that he exercised reasonable diligence 
during the critical period from just prior to opponent's entry 
into the field); Griffith v. Kanamaru, 816 F.2d 624, 2 
USPQ2d 1361 (Fed. Cir. 1987) (Court generally reviewed 
cases on excuses for inactivity including vacation extended 
by ill health and daily job demands, and held lack of uni-
versity funding and personnel are not acceptable excuses.); 
Litchfield v. Eigen, 535 F.2d 72, 190 USPQ 113 (CCPA 
1976) (budgetary limits and availability of animals for test-
ing not sufficiently described); Morway v. Bondi, 203 F.2d 
741, 749, 97 USPQ 318, 323 (CCPA 1953) (voluntarily 
laying aside inventive concept in pursuit of other projects is 
generally not an acceptable excuse although there may be 
circumstances creating exceptions);   Anderson v. Crowther, 
152 USPQ 504, 512 (Bd. Pat. Inter. 1965) (preparation of 
routine periodic reports covering all accomplishments of 
the laboratory insufficient to show diligence); Wu v. Jucker, 
167 USPQ 467, 472-73 (Bd. Pat. Inter. 1968) (applicant 
improperly allowed test data sheets to accumulate to a suf-
ficient amount to justify interfering with equipment then in 
use on another project); Tucker v. Natta, 171 USPQ 
494,498 (Bd. Pat. Inter. 1971) ("[a]ctivity directed toward 
the reduction to practice of a genus does not establish, 
prima facie, diligence toward the reduction to practice of a 
species embraced by said genus"); Justus v. Appenzeller, 
177 USPQ 332, 340-1 (Bd. Pat. Inter. 1971) (Although it is 
possible that patentee could have reduced the invention to 
practice in a shorter time by relying on stock items rather 
than by designing a particular piece of hardware, patentee 
exercised reasonable diligence to secure the required hard-
ware to actually reduce the invention to practice. "[I]n 
deciding the question of diligence it is immaterial that the 
inventor may not have taken the expeditious course?.").

WORK RELIED UPON TO SHOW REASONABLE 
DILIGENCE MUST BE DIRECTLY RELATED TO 
THE REDUCTION TO PRACTICE

The work relied upon to show reasonable diligence must 
be directly related to the reduction to practice of the inven-
tion in issue. Naber v. Cricchi, 567 F.2d 382, 384, 196 
USPQ 294, 296 (CCPA 1977), cert. denied, 439 U.S. 826 
(1978). "[U]nder some circumstances an inventor should 
also be able to rely on work on closely related inventions as 
support for diligence toward the reduction to practice on an 
invention in issue." Ginos v. Nedelec, 220 USPQ 831, 836 
(Bd. Pat. Inter. 1983) (work on other closely related com-
pounds that were considered to be part of the same inven-
tion and which were included as part of a grandparent 
application). "The work relied upon must be directed to 
attaining a reduction to practice of the subject matter of the 
counts. It is not sufficient that the activity relied on con-
cerns related subject matter." Gunn v. Bosch, 181 USPQ 
758, 761 (Bd. Pat. Inter. 1973) (An actual reduction to prac-
tice of the invention at issue which occurred when the 
inventor was working on a different invention "was fortu-
itous, and not the result of a continuous intent or effort to 
reduce to practice the invention here in issue. Such fortu-
itousness is inconsistent with the exercise of diligence 
toward reduction to practice of that invention." 181 USPQ 
at 761. Furthermore, evidence drawn towards work on 
improvement of samples or specimens generally already in 
use at the time of conception that are but one element of the 
oscillator circuit of the count does not show diligence 
towards the construction and testing of the overall combi-
nation.); Broos v. Barton, 142 F.2d 690, 691, 61 USPQ 447, 
448 (CCPA 1944) (preparation of application in U.S. for 
foreign filing constitutes diligence); De Solms v. Schoen-
wald, 15 USPQ2d 1507 (Bd. Pat. App. & Inter. 1990) (prin-
ciples of diligence must be given to inventor's 
circumstances including skill and time; requirement of cor-
roboration applies only to testimony of inventor); Huelster 
v. Reiter, 168 F.2d 542, 78 USPQ 82 (CCPA 1948) (if 
inventor was not able to make an actual reduction to prac-
tice of the invention, he must also show why he was not 
able to constructively reduce the invention to practice by 
the filing of an application).

DILIGENCE REQUIRED IN PREPARING AND FIL-
ING PATENT APPLICATION

The diligence of attorney in preparing and filing patent 
application inures to the benefit of the inventor. Conception 
was established at least as early as the date a draft of a 
patent application was finished by a patent attorney on 
behalf of the inventor. Conception is less a matter of signa-
ture than it is one of disclosure. Attorney does not prepare a 
patent application on behalf of particular named persons, 
but on behalf of the true inventive entity. Six days to exe-
cute and file application is acceptable. Haskell v. Cole-
burne, 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). 
See also   Bey v. Kollonitsch, 866 F.2d 1024, 231 USPQ 967 
(Fed. Cir. 1986) (Reasonable diligence is all that is required 
of the attorney. Reasonable diligence is established if attor-
ney worked reasonably hard on the application during the 
continuous critical period. If the attorney has a reasonable 
backlog of unrelated cases which he takes up in chronolog-
ical order and carries out expeditiously, that is sufficient. 
Work on a related case(s) that contributed substantially to 
the ultimate preparation of an application can be credited as 
diligence.).

END OF DILIGENCE PERIOD IS MARKED BY 
EITHER ACTUAL OR CONSTRUCTIVE REDUC-
TION TO PRACTICE

"[I]t is of no moment that the end of that period [for dili-
gence] is fixed by a constructive, rather than an actual, 
reduction to practice." Justus v. Appenzeller, 177 USPQ 
332, 340-1 (Bd. Pat. Inter. 1971).

2141	35 U.S.C. 103; The Graham Factual 
Inquiries  [R-1]

35 U.S.C. 103.  Conditions for patentability; non-obvious  subject 
matter.

(a)	A patent may not be obtained though the invention is not identi-
cally disclosed or described as set forth in section 102 of this title, if the 
differences between the subject matter sought to be patented and the prior 
art are such that the subject matter as a whole would have been obvious at 
the time the invention was made to a person having ordinary skill in the art 
to which said subject matter pertains. Patentability shall not be negatived 
by the manner in which the invention was made.

(b)(l)	Notwithstanding subsection (a), and upon timely election by 
the applicant for patent to proceed under this subsection, a biotechnologi-
cal process using or resulting in a composition of matter that is novel 
under section 102 and nonobvious under subsection (a) of this section 
shall be considered nonobvious if-

(A)	claims to the process and the composition of matter are con-
tained in either the same application for patent or in separate applications 
having the same effective filing date; and

(B)	the composition of matter, and the process at the time it was 
invented, were owned by the same person or subject to an obligation of 
assignment to the same person.

(2)	A patent issued on a process under paragraph (1)-

(A)	shall also contain the claims to the composition of matter 
used in or made by that process, or

(B)	shall, if such composition of matter is claimed in another 
patent, be set to expire on the same date as such other patent, notwith-
standing section 154.

(3)	For purposes of paragraph (1), the term "biotechnological pro-
cess" means-

(A)	a process of genetically altering or otherwise inducing a sin-
gle- or multi-celled organism to-

(i)	express an exogenous nucleotide sequence,

(ii)	inhibit, eliminate, augment, or alter expression of an 
endogenous nucleotide sequence, or

(iii)	express a specific physiological characteristic not natu-
rally associated with said organism;

(B)	cell fusion procedures yielding a cell line that expresses a 
specific protein, such as a monoclonal antibody; and

(C)	a method of using a product produced by a process defined 
by subparagraph (A) or (B), or a combination of subparagraphs (A) and 
(B).

**>

(c)	Subject matter developed by another person, which qualifies as 
prior art only under one or more subsections (e), (f), and (g) of section 102 
of this title, shall not preclude patentability under this section where the 
subject matter and the claimed invention were, at the time the invention 
was made, owned by the same person or subject to an obligation of assign-
ment to the same person.<

STANDARD OF PATENTABILITY TO BE APPLIED 
IN OBVIOUSNESS REJECTIONS

Patent examiners carry the responsibility of making sure 
that the standard of patentability enunciated by the 
Supreme Court and by the Congress is applied in each and 
every case. The Supreme Court in Graham v. John Deere, 
383 U.S. 1, 148 USPQ 459 (1966), stated:

Under ? 103, the scope and content of the prior art are to be 
determined; differences between the prior art and the claims at 
issue are to be ascertained; and the level of ordinary skill in the 
pertinent art resolved. Against this background, the obviousness 
or nonobviousness of the subject matter is determined. Such sec-
ondary considerations as commercial success, long felt but 
unsolved needs, failure of others, etc., might be utilized to give 
light to the circumstances surrounding the origin of the subject 
matter sought to be patented. As indicia of obviousness or nonob-
viousness, these inquires may have relevancy. . . 

       

This in not to say, however, that there will not be difficulties 
in applying the nonobviousness test. What is obvious is not a 
question upon which there is likely to be uniformity of thought in 
every given factual context. The difficulties, however, are com-
parable to those encountered daily by the courts in such frames of 
reference as negligence and scienter, and should be amenable to a 
case-by-case development. We believe that strict observance of 
the requirements laid down here will result in that uniformity and 
definitiveness which Congress called for in the 1952 Act.

Office policy has consistently been to follow   Graham v. 
John Deere Co. in the consideration and determination of 
obviousness under 35 U.S.C. 103. As quoted above, the 
four factual inquires enunciated therein as a background for 
determining obviousness are briefly as follows:

(A)	Determining of the scope and contents of the prior 
art;

(B)	Ascertaining the differences between the prior art 
and the claims in issue; 

(C)	Resolving the level of ordinary skill in the perti-
nent art; and 

(D)	Evaluating evidence of secondary considerations.

The Supreme Court reaffirmed and relied upon the Gra-
ham three pronged test in its consideration and determina-
tion of obviousness in the fact situations presented in both 
the Sakraida v. Ag Pro, Inc., 425 U.S. 273, 189 USPQ 449, 
reh'g denied, 426 U.S. 955 (1976) and Anderson's-Black 
Rock, Inc. v. Pavement Salvage Co., 396 U.S. 57, 163 
USPQ 673 (1969) decisions. In each case, the Court went 
on to discuss whether the claimed combinations produced a 
"new or different function"  and a "synergistic result," but 
clearly decided whether the claimed inventions were non-
obviousness on the basis of the three-way test in Graham. 
Nowhere in its decisions in those cases does the Court state 
that the "new or different function" and "synergistic result" 
tests supersede a finding of nonobvious or obviousness 
under the Graham test.

Accordingly, examiners should apply the test for patent-
ability under 35 U.S.C. 103 set forth in Graham. See below 
for a detailed discussion of each of the   Graham factual 
inquiries. It should be noted that the Supreme Court's 
application of the Graham test to the fact circumstances in 
Ag Pro was somewhat stringent, as it was in Black Rock. 
Note Republic Industries, Inc. v. Schlage Lock Co., 592 
F.2d 963, 200 USPQ 769 (7th Cir. 1979). The Court of 
Appeals for the Federal Circuit stated in Stratoflex, Inc. v. 
Aeroquip Corp., 713 F.2d 1530, 1540,  218 USPQ 871, 880 
(Fed. Cir. 1983) that

A requirement for "synergism" or a "synergistic effect" is 
nowhere found in the statute, 35 U.S.C. When present, for exam-
ple in a chemical case, synergism may point toward nonobvious-
ness, but its absence has no place in evaluating the evidence on 
obviousness. The more objective findings suggested in Graham, 
supra, are drawn from the language of the statute and are fully 
adequate guides for evaluating the evidence relating to compli-
ance with 35 U.S.C. ? 103. Bowser Inc. v. United States, 388 F. 
2d 346, 156 USPQ 406 (Ct. Cl. 1967).

BASIC CONSIDERATIONS WHICH APPLY TO 
OBVIOUSNESS REJECTIONS 

When applying 35 U.S.C. 103, the following tenets of 
patent law must be adhered to:

(A)	The claimed invention must be considered as a 
whole; 

(B)	The references must be considered as a whole and 
must suggest the desirability and thus the obviousness of 
making the combination; 

(C)	The references must be viewed without the benefit 
of impermissible hindsight vision afforded by the claimed 
invention and 

(D)	Reasonable expectation of success is the standard 
with which obviousness is determined.  

Hodosh v. Block Drug Co., Inc., 786 F.2d 1136, 1143 
n.5, 229 USPQ 182, 187 n.5 (Fed. Cir. 1986).

OBJECTIVE EVIDENCE MUST BE CONSIDERED

Objective evidence or secondary considerations such as 
unexpected results, commercial success, long-felt need, 
failure of others, copying by others, licensing, and skepti-
cism of experts are relevant to the issue of obviousness and 
must be considered in every case in which they are present. 
When evidence of any of these secondary considerations is 
submitted, the examiner must evaluate the evidence. The 
weight to be accorded to the evidence depends on the indi-
vidual factual circumstances of each case. Stratoflex, Inc. v. 
Aeroquip Corp., 713 F.2d 1530, 218 USPQ 871 (Fed. Cir. 
1983);   Hybritech, Inc. v. Monoclonal Antibodies, Inc., 802 
F.2d 1367, 231 USPQ 81 (Fed. Cir. 1986), cert. denied, 480 
U.S. 947 (1987). The ultimate determination on patentabil-
ity is made on the entire record. In re Oetiker, 977 F.2d 
1443, 1446, 24 USPQ2d 1443, 1445 (Fed. Cir. 1992).

See MPEP ? 716-  ? 716.06 for a discussion of objective 
evidence and its role in the final legal determination of 
whether a claimed invention would have been obvious 
under  35 U.S.C. 103.

2141.01	Scope and Content of the Prior Art  
[R-1]

I.	PRIOR ART AVAILABLE UNDER 35 U.S.C. 
102 IS AVAILABLE UNDER 35 U.S.C. 103

"Before answering Graham's `content' inquiry, it must 
be known whether a patent or publication is in the prior art 
under 35 U.S.C. ? 102." Panduit Corp. v. Dennison Mfg. 
Co., 810 F.2d 1561, 1568, 1 USPQ2d 1593, 1597 (Fed. 
Cir.), cert. denied, 481 U.S. 1052 (1987). Subject matter 
that is prior art under  35 U.S.C. 102 can be used to support 
a rejection under section 103. Ex parte Andresen, 212 
USPQ 100, 102 (Bd. Pat. App. & Inter. 1981) ("it appears 
to us that the commentator [of 35 U.S.C.A.] and the [con-
gressional] committee viewed section 103 as including all 
of the various bars to a patent as set forth in section 102.").

A 35 U.S.C. 103 rejection is based on 35 U.S.C. 102(a), 
102(b), 102(e), etc. depending on the type of prior art refer-
ence used and its publication or issue date. For instance, an 
obviousness rejection over a U.S. patent which was issued 
more than 1 year before the filing is said to be a statutory 
bar just as if it anticipated the claims under 102(b). Analo-
gously, an obviousness rejection based on a publication 
which would be applied under 102(a) if it anticipated the 
claims can be overcome by swearing behind the publication 
date of the reference by filing an affidavit or declaration 
under  37 CFR 1.131.

For an overview of what constitutes prior art under 
35 U.S.C. 102 see  MPEP ? 901 -  ? 901.06(d) and  ? 2121 
-  ? 2129.

II.	SUBSTANTIVE CONTENT OF THE PRIOR 
ART

See  MPEP ? 2121 -  ? 2129 for case law relating to the 
substantive content of the prior art (e.g., availability of 
inoperative devices, extent to which prior art must be 
enabling, broad disclosure rather than preferred embodi-
ments, admissions, etc.).

III.	CONTENT OF THE PRIOR ART IS DETER-
MINED AT THE TIME THE INVENTION WAS 
MADE TO AVOID HINDSIGHT

Requirement for "at the time the invention was made" is 
to avoid impermissible hindsight. See  MPEP ? 2145, para-
graph X.A. for a discussion of rebutting applicants' argu-
ments that a rejection is based on hindsight.

"It is difficult but necessary that the decisionmaker for-
get what he or she has been taught . . . about the claimed 
invention and cast the mind back to the time the invention 
was made (often as here many years), to occupy the mind 
of one skilled in the art who is presented only with the ref-
erences, and who is normally guided by the then-accepted 
wisdom in the art." W.L. Gore & Associates, Inc. v. Gar-
lock, Inc., 721 F.2d 1540, 220 USPQ 303, 313 (Fed. Cir. 
1983), cert. denied, 469 U.S. 851 (1984). 

IV.	35 U.S.C. 103(c) - EVIDENCE REQUIRED TO 
SHOW CONDITIONS OF 35 U.S.C. 103 APPLY

An applicant who wants to avail himself or herself of the 
benefits of  35 U.S.C. 103(c) has the burden of establishing 
that subject matter which qualifies as prior art under sub-
section >(e),< (f) or (g) of section 102 and the claimed 
invention were, at the time the invention was made, owned 
by the same person or subject to an obligation of assign-
ment to the same person. Ex parte Yoshino, 227 USPQ 52 
(Bd. Pat. App. & Inter. 1985). Note that >for applications 
filed prior to November 29, 1999,< 35 U.S.C. 103(c) is lim-
ited on its face to subject matter developed by another per-
son which qualifies as prior art only under subsection (f) or 
(g) of section 102.  >See MPEP ? 706.02(l)(1).  See also<  
In re Bartfeld, 925 F.2d 1450, 1453-54, 17 USPQ2d 1885, 
1888 (Fed. Cir. 1991) (Applicant attempted to overcome a  
35 U.S.C. 102(e)/103 rejection with a terminal disclaimer 
by alleging that the public policy intent of 35 U.S.C 103(c) 
was to prohibit the use of "secret" prior art in obviousness 
determinations. The court rejected this argument, holding 
"We may not disregard the unambiguous exclusion of 
? 102(e) from the statute's purview.").

See MPEP ? *>706.02(l)(2)< for the requirements which 
must be met to establish common ownership.

2141.01(a)	Analogous and Nonanalogous Art 

TO RELY ON A REFERENCE UNDER 35 U.S.C. 103, 
IT MUST BE ANALOGOUS PRIOR ART

The examiner must determine what is "analogous prior 
art" for the purpose of analyzing the obviousness of the 
subject matter at issue. "In order to rely on a reference as a 
basis for rejection of an applicant's invention, the reference 
must either be in the field of applicant's endeavor or, if not, 
then be reasonably pertinent to the particular problem with 
which the inventor was concerned." In re Oetiker, 977 F.2d 
1443, 1446, 24 USPQ2d 1443, 1445 (Fed. Cir. 1992). See 
also In re Deminski, 796 F.2d 436, 230 USPQ 313 (Fed. 
Cir. 1986); In re Clay, 966 F.2d 656, 659, 23 USPQ2d 
1058, 1060-61 (Fed. Cir. 1992) ("A reference is reasonably 
pertinent if, even though it may be in a different field from 
that of the inventor's endeavor, it is one which, because of 
the matter with which it deals, logically would have com-
mended itself to an inventor's attention in considering his 
problem."); and Wang Laboratories Inc. v. Toshiba Corp., 
993 F.2d 858, 26 USPQ2d 1767 (Fed. Cir. 1993). 

PTO CLASSIFICATION IS SOME EVIDENCE OF 
ANALOGY, BUT SIMILARITIES AND DIFFER-
ENCES IN STRUCTURE AND FUNCTION CARRY 
MORE WEIGHT

While Patent Office classification of references and the 
cross-references in the official search notes are some evi-
dence of "nonanalogy" or "analogy" respectively, the court 
has found "the similarities and differences in structure and 
function of the inventions to carry far greater weight." In re 
Ellis, 476 F.2d 1370, 1372, 177 USPQ 526, 527 (CCPA 
1973) (The structural similarities and functional overlap 
between the structural gratings shown by one reference and 
the shoe scrapers of the type shown by another reference 
were readily apparent, and therefore the arts to which the 
reference patents belonged were reasonably pertinent to the 
art with which appellant's invention dealt (pedestrian floor 
gratings).); In re Clay, 966 F.2d 656, 23 USPQ2d 1058 
(Fed. Cir. 1992) (Claims were directed to a process for stor-
ing a refined liquid hydrocarbon product in a storage tank 
having a dead volume between the tank bottom and its out-
let port wherein a gelled solution filled the tank's dead vol-
ume to prevent loss of stored product while preventing 
contamination. One of the references relied upon disclosed 
a process for reducing the permeability of natural under-
ground hydrocarbon bearing formations using a gel similar 
to that of applicant to improve oil production. The court 
disagreed with the PTO's argument that the reference and 
claimed inventions were part of the same endeavor, "maxi-
mizing withdrawal of petroleum stored in petroleum 
reserves," and found that the inventions involved different 
fields of endeavor since the reference taught the use of the 
gel in a different structure for a different purpose under dif-
ferent temperature and pressure conditions, and since the 
application related to storage of liquid hydrocarbons rather 
than extraction of crude petroleum. The court also found 
the reference was not reasonably pertinent to the problem 
with which the inventor was concerned because a person 
having ordinary skill in the art would not reasonably have 
expected to solve the problem of dead volume in tanks for 
refined petroleum by considering a reference dealing with 
plugging underground formation anomalies.).

ANALOGY IN THE CHEMICAL ARTS

See, for example, Ex parte Bland, 3 USPQ2d 1103 (Bd. 
Pat App. & Inter. 1986) (Claims were drawn to a particulate 
composition useful as a preservative for an animal food-
stuff (or a method of inhibiting fungus growth in an animal 
foodstuff therewith) comprising verxite having absorbed 
thereon propionic acid. All references were concerned with 
absorbing biologically active materials on carriers, and 
therefore the teachings in each of the various references 
would have been pertinent to the problems in the other ref-
erences and the invention at hand.); Stratoflex, Inc. v. Aero-
quip Corp., 713 F.2d 1530, 218 USPQ 871 (Fed. Cir. 1983) 
(Problem confronting inventor was preventing electrostatic 
buildup in PTFE tubing caused by hydrocarbon fuel flow 
while precluding leakage of fuel. Two prior art references 
relied upon were in the rubber hose art, both referencing the 
problem of electrostatic buildup caused by fuel flow. The 
court found that because PTFE and rubber are used by the 
same hose manufacturers and experience the same and sim-
ilar problems, a solution found for a problem experienced 
with either PTFE or rubber hosing would be looked to 
when facing a problem with the other.); In re Mlot-
Fijalkowski, 676 F.2d 666, 213 USPQ 713 (CCPA 1982) 
(Problem faced by appellant was enhancement and immo-
bilization of dye penetrant indications. References which 
taught the use of dyes and finely divided developer materi-
als to produce colored images preferably in, but not limited 
to, the duplicating paper art were properly relied upon 
because the court found that appellant's problem was one 
of dye chemistry, and a search for its solution would 
include the dye arts in general.).

ANALOGY IN THE MECHANICAL ARTS

See, for example, In re Oetiker, 977 F.2d 1443, 24 
USPQ2d 1443 (Fed. Cir. 1992) (Applicant claimed 
an improvement in a hose clamp which differed from the 
prior art in the presence of a preassembly "hook" which 
maintained the preassembly condition of the clamp and dis-
engaged automatically when the clamp was tightened. The 
Board relied upon a reference which disclosed a hook 
and eye fastener for use in garments, reasoning that all 
hooking problems are analogous. The court held the refer-
ence was not within the field of applicant's endeavor, and 
was not reasonably pertinent to the particular problem with 
which the inventor was concerned because it had not been 
shown that a person of ordinary skill, seeking to solve a 
problem of fastening a hose clamp, would reasonably be 
expected or motivated to look to fasteners for garments. 
The Commissioner further argued in the brief on appeal 
that a disengageable catch is a common everyday mechani-
cal concept, however the court held that the Commissioner 
did not explain why a "catch" of unstated structure is such a 
concept, and why it would have made the claimed inven-
tion obvious.). Compare Stevenson v. International Trade 
Comm., 612 F.2d 546, 550, 204 USPQ 276, 280 (CCPA 
1979) ("In a simple mechanical invention a broad spectrum 
of prior art must be explored and it is reasonable to permit 
inquiry into other areas where one of ordinary skill in the 
art would be aware that similar problems exist.").

Also see   In re Deminski, 796 F.2d 436, 230 USPQ 313 
(Fed. Cir. 1986) (Applicant's claims related to double-act-
ing high pressure gas transmission line compressors in 
which the valves could be removed easily for replacement. 
The  Board relied upon references which taught either a 
double-acting piston pump or a double-acting piston com-
pressor. The court agreed that since the cited pumps and 
compressors have essentially the same function and struc-
ture, the field of endeavor includes both types of double-
action piston devices for moving fluids.); Pentec, Inc. v. 
Graphic Controls Corp., 776 F.2d 309, 227 USPQ 766 
(Fed. Cir. 1985) (Claims at issue were directed to an instru-
ment marker pen body, the improvement comprising a pen 
arm holding means having an integrally molded hinged 
member for folding over against the pen body. Although 
the patent owners argued the hinge and fastener art was 
nonanalogous, the court held that the problem confronting 
the inventor was the need for a simple holding means to 
enable frequent, secure attachment and easy removal of a 
marker pen to and from a pen arm, and one skilled in the 
pen art trying to solve that problem would have looked to 
the fastener and hinge art.); and Ex parte Goodyear Tire & 
Rubber Co., 230 USPQ 357 (Bd. Pat. App. & Inter. 1985) 
(A reference in the clutch art was held reasonably pertinent 
to the friction problem faced by applicant, whose claims 
were directed to a braking material, because brakes and 
clutches utilize interfacing materials to accomplish their 
respective purposes.).

ANALOGY IN THE ELECTRICAL ARTS

See, for example, Wang Laboratories, Inc. v. Toshiba 
Corp., 993 F.2d 858, 26 USPQ2d 1767 (Fed. Cir. 1993) 
(Patent claims were directed to single in-line memory mod-
ules (SIMMs) for installation on a printed circuit mother-
board for use in personal computers. Reference to a SIMM 
for an industrial controller was not necessarily in the same 
field of endeavor as the claimed subject matter merely 
because it related to memories. Reference was found to be 
in a different field of endeavor because it involved memory 
circuits in which modules of varying sizes may be added or 
replaced, whereas the claimed invention involved compact 
modular memories. Furthermore, since memory modules of 
the claims at issue were intended for personal computers 
and used dynamic random-access-memories, whereas ref-
erence SIMM was developed for use in large industrial 
machine controllers and only taught the use of static ran-
dom- access-memories or read-only-memories, the finding 
that the reference was nonanalogous was supported by sub-
stantial evidence.); Medtronic, Inc. v. Cardiac Pacemakers, 
721 F.2d 1563, 220 USPQ 97 (Fed. Cir. 1983) (Patent 
claims were drawn to a cardiac pacemaker which com-
prised, among other components, a runaway inhibitor 
means for preventing a pacemaker malfunction from caus-
ing pulses to be applied at too high a frequency rate. Two 
references disclosed circuits used in high power, high fre-
quency devices which inhibited the runaway of pulses from 
a pulse source. The court held that one of ordinary skill in 
the pacemaker designer art faced with a rate-limiting prob-
lem would look to the solutions of others faced with rate 
limiting problems, and therefore the references were in an 
analogous art.).

EXAMPLES OF ANALOGY IN THE DESIGN ARTS

See  MPEP ? 1504.03 for a discussion of the relevant 
case law setting forth the general requirements for analo-
gous art in design applications.

For examples of analogy in the design arts, see In re 
Rosen, 673 F.2d 388, 213 USPQ 347 (CCPA 1982) (The 
design at issue was a coffee table of contemporary styling. 
The court held designs of contemporary furniture other 
than coffee tables, such as the desk and circular glass table 
top designs of the references relied upon, would reasonably 
fall within the scope of the knowledge of the designer 
of ordinary skill.); Ex parte Pappas, 23 USPQ2d 1636 (Bd. 
Pat. App. & Inter. 1992) (At issue was an ornamental 
design for a feed bunk with an inclined corner configura-
tion. Examiner relied upon references to a bunk lacking 
the inclined corners claimed by appellant and the Architec-
tural Precast Concrete Drafting Handbook. The Board 
found the Architectural Precast Concrete Drafting Hand-
book was analogous art, noting that a bunk may be a wood 
or concrete trough, and that both references relied upon 
"disclose structures in which at least one upstanding leg is 
generally perpendicular to a base portion to define a corner 
configuration between the leg and base portion."); In re 
Butera, 1 F.3d 1252, 28 USPQ2d 1399 (Fed. Cir. 1993) 
(unpublished - not citable as precedent) (The claimed 
invention, a spherical design for a combined insect repel-
lant and air freshener, was rejected by the Board as obvious 
over a single reference to a design for a metal ball anode. 
The court reversed, holding the reference design to be 
nonanalogous art. "A prior design is of the type claimed if 
it has the same general use as that claimed in  the design 
patent application . . . . One designing a combined insect 
repellant and air freshener would therefore not have reason 
to know of or look to a design for a metal ball anode." 28 
USPQ2d at 1400.). 

2141.02	Differences Between Prior Art and 
Claimed Invention 

Ascertaining the differences between the prior art and 
the claims at issue requires interpreting the claim language, 
and considering both the invention and the prior art refer-
ences as a whole. See  MPEP ? 2111 -  ? 2116.01 for case 
law pertaining to claim interpretation.

THE CLAIMED INVENTION AS A WHOLE MUST 
BE CONSIDERED

In determining the differences between the prior art and 
the claims, the question under  35 U.S.C. 103 is not 
whether the differences themselves would have been obvi-
ous, but whether the claimed invention as a whole would 
have been obvious. Stratoflex, Inc. v. Aeroquip Corp., 713 
F.2d 1530, 218 USPQ 871 (Fed. Cir. 1983); Schenck v. 
Nortron Corp., 713 F.2d 782, 218 USPQ 698 (Fed. Cir. 
1983) (Claims were directed to a vibratory testing machine 
(a hard-bearing wheel balancer) comprising a holding 
structure, a base structure, and a supporting means which 
form "a single integral and gaplessly continuous piece." 
Nortron argued the invention is just making integral what 
had been made in four bolted pieces, improperly limiting 
the focus to a structural difference from the prior art and 
failing to consider the invention as a whole. The prior art 
perceived a need for mechanisms to dampen resonance, 
whereas the inventor eliminated the need for dampening 
via the one-piece gapless support structure. "Because that 
insight was contrary to the understandings and expectations 
of the art, the structure effectuating it would not have been 
obvious to those skilled in the art." 713 F.2d at 785, 218 
USPQ at 700 (citations omitted).).

See also In re Hirao, 535 F.2d 67, 190 USPQ 15 (CCPA 
1976) (Claims were directed to a three step process for pre-
paring sweetened foods and drinks. The first two steps were 
directed to a process of producing high purity maltose (the 
sweetener), and the third was directed to adding the maltose 
to foods and drinks. The parties agreed that the first two 
steps were unobvious but formed a known product and the 
third step was obvious. The Solicitor argued the preamble 
was directed to a process for preparing foods and drinks 
sweetened mildly and thus the specific method of making 
the high purity maltose (the first two steps in the claimed 
process) should not be given weight, analogizing with 
product-by-process claims. The court held "due to the 
admitted unobviousness of the first two steps of the 
claimed combination of steps, the subject matter as a whole 
would not have been obvious to one of ordinary skill in the 
art at the time the invention was made." 535 F.2d at 69, 190 
USPQ at 17 (emphasis in original). The preamble only 
recited the purpose of the process and did not limit the body 
of the claim. Therefore, the claimed process was a three 
step process, not the product formed by two steps of the 
process or the third step of using that product.). 

DISTILLING THE INVENTION DOWN TO A 
"GIST" OR "THRUST" OF AN INVENTION DISRE-
GARDS "AS A WHOLE" REQUIREMENT

Distilling an invention down to the "gist" or "thrust" of 
an invention disregards the requirement of analyzing the 
subject matter "as a whole." W.L. Gore & Associates, Inc. v. 
Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 
1983), cert. denied, 469 U.S. 851 (1984) (restricting con-
sideration of the claims to a 10% per second rate of stretch-
ing of unsintered PTFE and disregarding other limitations 
resulted in treating claims as though they read differently 
than allowed); Bausch & Lomb v. Barnes-Hind/
Hydrocurve, Inc., 796 F.2d 443, 447-49, 230 USPQ 416, 
419-20 (Fed. Cir. 1986), cert. denied, 484 U.S. 823 (1987) 
(District court focused on the "concept of forming ridgeless 
depressions having smooth rounded edges using a laser 
beam to vaporize the material," but "disregarded express 
limitations that the product be an ophthalmic lens formed 
of a transparent cross-linked polymer and that the laser 
marks be surrounded by a smooth surface of unsublimated 
polymer."). See also Jones v. Hardy, 727 F.2d 1524, 1530, 
220 USPQ 1021, 1026 (Fed. Cir. 1984) ("treating the 
advantage as the invention disregards statutory requirement 
that the invention be viewed `as a whole' "); Panduit Corp. 
v. Dennison Mfg. Co., 810 F.2d 1561, 1 USPQ2d 1593 
(Fed. Cir.), cert. denied, 481 U.S. 1052 (1987) (district 
court improperly distilled claims down to a one word solu-
tion to a problem).

DISCOVERING SOURCE/CAUSE OF A PROBLEM 
IS PART OF "AS A WHOLE" INQUIRY

"[A] patentable invention may lie in the discovery of  the 
source of a problem even though the remedy may be obvi-
ous once the source of the problem is identified. This is part 
of the `subject matter as a whole' which should always be 
considered in determining the obviousness of an invention 
under 35 U.S.C. ? 103." In re Sponnoble, 405 F.2d 578, 
585, 160 USPQ 237, 243 (CCPA 1969). However, "discov-
ery of the cause of a problem . . does not always result in a 
patentable invention. . . . [A] different situation exists 
where the solution is obvious from prior art which contains 
the same solution for a similar problem." In re Wiseman, 
596 F.2d 1019, 1022, 201 USPQ 658, 661 (CCPA 1979) 
(emphasis in original). 

In In re Sponnoble, the claim was directed to a plural 
compartment mixing vial wherein a center seal plug was 
placed between two compartments for temporarily isolating 
a liquid-containing compartment from a solids-containing 
compartment. The claim differed from the prior art in the 
selection of butyl rubber with a silicone coating as the plug 
material instead of natural rubber. The prior art recognized 
that leakage from the liquid to the solids compartment was 
a problem, and considered the problem to be a result of 
moisture passing around the center plug because of micro-
scopic fissures inherently present in molded or blown glass. 
The court found the inventor discovered the cause of mois-
ture transmission was through the center plug, and there 
was no teaching in the prior art which would suggest the 
necessity of selecting applicant's plug material which was 
more impervious to liquids than the natural rubber plug of 
the prior art.

In In re Wiseman, 596 F.2d at 1022, 201 USPQ at 661, 
claims directed to grooved carbon disc brakes wherein the 
grooves were provided to vent steam or vapor during a 
braking action to minimize fading of the brakes were 
rejected as obvious over a reference showing carbon disc 
brakes without grooves in combination with a reference 
showing grooves in noncarbon disc brakes for the purpose 
of cooling the faces of the braking members and eliminat-
ing dust, thereby reducing fading of the brakes. The court 
affirmed the rejection, holding that even if applicants dis-
covered the cause of a problem, the solution would have 
been obvious from the prior art which contained the same 
solution (inserting grooves in disc brakes) for a similar 
problem.

APPLICANTS ALLEGING DISCOVERY OF A 
SOURCE OF A PROBLEM MUST PROVIDE SUB-
STANTIATING EVIDENCE

Applicants who allege they discovered the source of a 
problem must provide evidence substantiating the allega-
tion, either by way of affidavits or declarations, or by way 
of a clear and persuasive assertion in the specification. In re 
Wiseman, 596 F.2d 1019, 201 USPQ 658 (CCPA 1979) 
(unsubstantiated statement of counsel was insufficient to 
show appellants discovered source of the problem); In re 
Kaslow, 707 F.2d 1366, 217 USPQ 1089 (Fed. Cir. 1983) 
(Claims were directed to a method for redeeming merchan-
dising coupons which contain a UPC "5-by-5" bar code 
wherein, among other steps, the memory at each supermar-
ket would identify coupons by manufacturer and transmit 
the data to a central computer to provide an audit thereby 
eliminating the need for clearinghouses and preventing 
retailer fraud. In challenging the propriety of an obvious-
ness rejection, appellant argued he discovered the source of 
a problem (retailer fraud and manual clearinghouse opera-
tions) and its solution. The court found appellant's specifi-
cation did not support the argument that he discovered the 
source of the problem with respect to retailer fraud, and that 
the claimed invention failed to solve the problem of manual 
clearinghouse operations.).

DISCLOSED INHERENT PROPERTIES ARE PART 
OF "AS A WHOLE" INQUIRY

"In determining whether the invention as a whole would 
have been obvious under 35 U.S.C. 103, we must first 
delineate the invention as a whole. In delineating the inven-
tion as a whole, we look not only to the subject matter 
which is literally recited in the claim in question... but also 
to those properties of the subject matter which are inherent 
in the subject matter and are disclosed in the specification. . 
. Just as we look to a chemical and its properties when we 
examine the obviousness of a composition of matter claim, 
it is this invention as a whole, and not some part of it, 
which must be obvious under  35 USC 103." In re Antonie, 
559 F.2d 618, 620, 195 USPQ 6,8 (CCPA 1977) (emphasis 
in original) (citations omitted) (The claimed wastewater 
treatment device had a tank volume to contractor area of 
0.12 gal./sq. ft. The court found the invention as a whole 
was the ratio of 0.12 and its inherent property that the 
claimed devices maximized treatment capacity regardless 
of other variables in the devices. The prior art did not rec-
ognize that treatment capacity was a function of the tank 
volume to contractor ratio, and therefore the parameter 
optimized was not recognized in the art to be a result-effec-
tive variable.). See also In re Papesch, 315 F.2d 381, 391, 
137 USPQ 43, 51 (CCPA 1963) ("From the standpoint of 
patent law, a compound and all its properties are insepara-
ble.").

Obviousness cannot be predicated on what is not known 
at the time an invention is made, even if the inherency of a 
certain feature is later established. In re Rijckaert, 9 F.2d 
1531, 28 USPQ2d 1955 (Fed. Cir. 1993). See MPEP ? 2112 
for the requirements of rejections based on inherency.

PRIOR ART MUST BE CONSIDERED IN ITS 
ENTIRETY, INCLUDING DISCLOSURES THAT 
TEACH AWAY FROM THE CLAIMS

A prior art reference must be considered in its entirety, 
i.e., as a whole, including portions that would lead away 
from the claimed invention. W.L. Gore & Associates, Inc. v. 
Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 
1983), cert. denied, 469 U.S. 851 (1984) (Claims were 
directed to a process of producing a porous article by 
expanding shaped, unsintered, highly crystalline poly(tet-
rafluoroethylene) (PTFE) by stretching said PTFE at a 10% 
per second rate to more than five times the original length. 
The prior art teachings with regard to unsintered PTFE 
indicated the material does not respond to conventional 
plastics processing, and the material should be stretched 
slowly. A reference teaching rapid stretching of conven-
tional plastic polypropylene with reduced crystallinity 
combined with a reference teaching stretching unsintered 
PTFE would not suggest rapid stretching of highly crystal-
line PTFE, in light of the disclosures in the art that teach 
away from the invention, i.e., that the conventional 
polypropylene should have reduced crystallinity before 
stretching, and that PTFE should be stretched slowly.).

2141.03	Level of Ordinary Skill in the Art

FACTORS TO CONSIDER IN DETERMINING 
LEVEL OF ORDINARY SKILL 

"Factors that may be considered in determining level of 
ordinary skill in the art include (1) the educational level of 
the inventor; (2) type of problems encountered in the art; 
(3) prior art solutions to those problems; (4) rapidity with 
which innovations are made; (5) sophistication of the tech-
nology; and (6) educational level of active workers in the 
field." Environmental Designs, Ltd. v. Union Oil Co., 713 
F.2d 693, 696, 218 USPQ 865, 868 (Fed. Cir. 1983), cert. 
denied, 464 U.S. 1043 (1984). 

The "hypothetical `person having ordinary skill in the 
art' to which the claimed subject matter pertains would, of 
necessity have the capability of understanding the scientific 
and engineering principles applicable to the pertinent art." 
Ex parte Hiyamizu, 10 USPQ2d 1393, 1394 (Bd. Pat. App. 
& Inter. 1988) (The Board disagreed with the examiner's 
definition of one of ordinary skill in the art (a doctorate 
level engineer or scientist working at least 40 hours per 
week in semiconductor research or development), finding 
that the hypothetical person is not definable by way of cre-
dentials, and that the evidence in the application did not 
support the conclusion that such a person would require a 
doctorate or equivalent knowledge in science or engineer-
ing.). 

References which do not qualify as prior art because 
they postdate the claimed invention may be relied upon to 
show the level of ordinary skill in the art at or around the 
time the invention was made. Ex parte Erlich, 22 USPQ 
1463 (Bd. Pat. App. & Inter. 1992).

SPECIFYING A PARTICULAR LEVEL OF SKILL IS 
NOT NECESSARY WHERE THE PRIOR ART 
ITSELF REFLECTS AN APPROPRIATE LEVEL

If the only facts of record pertaining to the level of skill 
in the art are found within the prior art of record, the court 
has held that an invention may be held to have been obvi-
ous without a specific finding of a particular level of skill 
where the prior art itself reflects an appropriate level. 
Chore-Time Equipment, Inc. v. Cumberland Corp., 713 
F.2d 774, 218 USPQ 673 (Fed. Cir. 1983). 

ASCERTAINING LEVEL OF ORDINARY SKILL IS 
NECESSARY TO MAINTAIN OBJECTIVITY

"The importance of resolving the level of ordinary skill 
in the art lies in the necessity of maintaining objectivity in 
the obviousness inquiry." Ryko Mfg. Co. v. Nu-Star, Inc., 
950 F.2d 714, 718, 21 USPQ2d 1053, 1057 (Fed. Cir. 
1991). The examiner must ascertain what would have been 
obvious to one of ordinary skill in the art at the time the 
invention was made, and not to the inventor, a judge, a lay-
man, those skilled in remote arts, or to geniuses in the art at 
hand. Environmental Designs, Ltd. v. Union Oil Co., 713 
F.2d 693, 218 USPQ 865 (Fed. Cir. 1983), cert. denied, 464 
U.S. 1043 (1984). 

2142	Legal Concept of Prima Facie  
Obviousness 

The legal concept of prima facie obviousness is a proce-
dural tool of examination which applies broadly to all arts. 
It allocates who has the burden of going forward with pro-
duction of evidence in each step of the examination pro-
cess. See In re Rinehart, 531 F.2d 1048, 189 USPQ 143 
(CCPA 1976); In re Linter, 458 F.2d 1013, 173 USPQ 560 
(CCPA 1972); In re Saunders, 444 F.2d 599, 170 USPQ 
213 (CCPA 1971); In re Tiffin, 443 F.2d 394, 170 USPQ 88 
(CCPA 1971), amended, 448 F.2d 791, 171 USPQ 294 
(CCPA 1971); In re Warner, 379 F.2d 1011, 154 USPQ 173 
(CCPA 1967), cert. denied, 389 U.S. 1057 (1968). The 
examiner bears the initial burden of factually supporting 
any prima facie conclusion of obviousness. If the examiner 
does not produce a prima facie case, the applicant is under 
no obligation to submit evidence of nonobviousness. If, 
however, the examiner does produce a prima facie case, the 
burden of coming forward with evidence or arguments 
shifts to the applicant who may submit additional evidence 
of nonobviousness, such as comparative test data showing 
that the claimed invention possesses improved properties 
not expected by the prior art. The initial evaluation of 
prima facie obviousness thus relieves both the examiner 
and applicant from evaluating evidence beyond the prior art 
and the evidence in the specification as filed until the art 
has been shown to suggest the claimed invention.

To reach a proper determination under 35 U.S.C. 103, 
the examiner must step backward in time and into the shoes 
worn by the hypothetical "person of ordinary skill in the 
art" when the invention was unknown and just before it was 
made. In view of all factual information, the examiner must 
then make a determination whether the claimed invention 
"as a whole" would have been obvious at that time to that 
person. Knowledge of applicant's disclosure must be put 
aside in reaching this determination, yet kept in mind in 
order to determine the "differences," conduct the search 
and evaluate the "subject matter as a whole" of the inven-
tion. The tendency to resort to "hindsight" based upon 
applicant's disclosure is often difficult to avoid due to the 
very nature of the examination process. However, imper-
missible hindsight must be avoided and the legal conclu-
sion must be reached on the basis of the facts gleaned from 
the prior art. 

ESTABLISHING A PRIMA FACIE CASE OF OBVI-
OUSNESS

To establish a prima facie case of obviousness, three 
basic criteria must be met. First, there must be some sug-
gestion or motivation, either in the references themselves or 
in the knowledge generally available to one of ordinary 
skill in the art, to modify the reference or to combine refer-
ence teachings. Second, there must be a reasonable expec-
tation of success. Finally, the prior art reference (or 
references when combined) must teach or suggest all the 
claim limitations. The teaching or suggestion to make the 
claimed combination and the reasonable expectation of 
success must both be found in the prior art, and not based 
on applicant's disclosure. In re Vaeck, 947 F.2d 488, 20 
USPQ2d 1438 (Fed. Cir. 1991). See MPEP ? 2143 - 
? 2143.03 for decisions pertinent to each of these criteria.

The initial burden is on the examiner to provide some 
suggestion of the desirability of doing what the inventor 
has done. "To support the conclusion that the claimed 
invention is directed to obvious subject matter, either the 
references must expressly or impliedly suggest the claimed 
invention or the examiner must present a convincing line of 
reasoning as to why the artisan would have found the 
claimed invention to have been obvious in light of the 
teachings of the references." Ex parte Clapp, 227 USPQ 
972, 973 (Bd. Pat. App. & Inter. 1985). See  MPEP ? 2144 
-  ? 2144.09 for examples of reasoning supporting obvious-
ness rejections.

When the motivation to combine the teachings of the ref-
erences is not immediately apparent, it is the duty of the 
examiner to explain why the combination of the teachings 
is proper. Ex parte Skinner, 2 USPQ2d 1788 (Bd. Pat. App. 
& Inter. 1986). A statement of a rejection that includes a 
large number of rejections must explain with reasonable 
specificity at least one rejection, otherwise the examiner 
procedurally fails to establish a prima facie case of obvi-
ousness. Ex parte Blanc, 13 USPQ2d 1383 (Bd. Pat. App. 
& Inter. 1989) (Rejection based on nine references which 
included at least 40 prior art rejections without explaining 
any one rejection with reasonable specificity was reversed 
as procedurally failing to establish a prima facie case of 
obviousness.).

If the examiner determines there is factual support for 
rejecting the claimed invention under 35 U.S.C. 103, the 
examiner must then consider any evidence supporting the 
patentability of the claimed invention, such as any evidence 
in the specification or any other evidence submitted by the 
applicant. The ultimate determination of patentability is 
based on the entire record, by a preponderance of evidence, 
with due consideration to the persuasiveness of any argu-
ments and any secondary evidence. In re Oetiker, 977 F.2d 
1443, 24 USPQ2d 1443 (Fed. Cir. 1992). The legal stan-
dard of "a preponderance of evidence" requires the evi-
dence to be more convincing than the evidence which is 
offered in opposition to it. With regard to rejections under  
35 U.S.C. 103, the examiner must provide evidence which 
as a whole shows that the legal determination sought to be 
proved (i.e., the reference teachings establish a prima facie 
case of obviousness) is more probable than not.

When an applicant submits evidence, whether in the 
specification as originally filed or in reply to a rejection, 
the examiner must reconsider the patentability of the 
claimed invention. The decision on patentability must be 
made based upon consideration of all the evidence, includ-
ing the evidence submitted by the examiner and the evi-
dence submitted by the applicant. A decision to make or 
maintain a rejection in the face of all the evidence must 
show that it was based on the totality of the evidence. Facts 
established by rebuttal evidence must be evaluated along 
with the facts on which the conclusion of obviousness was 
reached, not against the conclusion itself. In re Eli Lilly & 
Co., 902 F.2d 943, 14 USPQ2d 1741 (Fed. Cir. 1990).

See In re Piasecki, 745 F.2d 1468, 223 USPQ 785 (Fed. 
Cir. 1984) for a discussion of the proper roles of the exam-
iner's prima facie case and applicant's rebuttal evidence in 
the final determination of obviousness. See MPEP 
? 706.02(j) for a discussion of the proper contents of a 
rejection under  35 U.S.C. 103.

2143	Basic Requirements of a Prima Facie 
Case of Obviousness 

To establish a prima facie case of obviousness, three 
basic criteria must be met. First, there must be some sug-
gestion or motivation, either in the references themselves or 
in the knowledge generally available to one of ordinary 
skill in the art, to modify the reference or to combine refer-
ence teachings. Second, there must be a reasonable expec-
tation of success. Finally, the prior art reference (or 
references when combined) must teach or suggest all the 
claim limitations.

The teaching or suggestion to make the claimed combi-
nation and the reasonable expectation of success must both 
be found in the prior art, not in applicant's disclosure. In re 
Vaeck, 947 F.2d 488, 20 USPQ2d 1438 (Fed. Cir. 1991). 

2143.01	Suggestion or Motivation to Modify 
the References  [R-1]

THE PRIOR ART MUST SUGGEST THE DESIR-
ABILITY OF THE CLAIMED INVENTION 

 >"There are three possible sources for a motivation to 
combine references: the nature of the problem to be solved, 
the teachings of the prior art, and the knowledge of persons 
of ordinary skill in the art." In re Rouffet, 149 F.3d 1350, 
1357, 47 USPQ2d 1453, 1457-58 (Fed. Cir. 1998)(The 
combination of the references taught every element of the 
claimed invention, however without a motivation to com-
bine, a rejection based on a prima facie case of obvious was 
held improper.).  The level of skill in the art cannot be 
relied upon to provide the suggestion to combine refer-
ences. Al-Site Corp. v. VSI Int'l Inc., 174 F.3d 1308, 50 
USPQ2d 1161 (Fed. Cir. 1999).<

"In determining the propriety of the Patent Office case 
for obviousness in the first instance, it is necessary to ascer-
tain whether or not the reference teachings would appear to 
be sufficient for one of ordinary skill in the relevant art 
having the reference before him to make the proposed sub-
stitution, combination, or other modification." In re Linter, 
458 F.2d 1013, 1016, 173 USPQ 560, 562 (CCPA 1972).

Obviousness can only be established by combining or 
modifying the teachings of the prior art to produce the 
claimed invention where there is some teaching, sugges-
tion, or motivation to do so found either in the references 
themselves or in the knowledge generally available to one 
of ordinary skill in the art. In re Fine, 837 F.2d 1071, 5 
USPQ2d 1596 (Fed. Cir. 1988); In re Jones, 958 F.2d 347, 
21 USPQ2d 1941 (Fed. Cir. 1992).

In In re Fine, the claims were directed to a system for 
detecting and measuring minute quantities on nitrogen 
compounds comprising a gas chromatograph, a converter 
which converts nitrogen compounds into nitric oxide by 
combustion, and a nitric oxide detector. The primary refer-
ence disclosed a system for monitoring sulfur compounds 
comprising a chromatograph, combustion means, and a 
detector, and the secondary reference taught nitric oxide 
detectors. The examiner and Board asserted that it would 
have been within the skill of the art to substitute one type of 
detector for another in the system of the primary reference, 
however the court found there was no support or explana-
tion of this conclusion and reversed.

In In re Jones, the claimed invention was the 2-(2?-ami-
noethoxy) ethanol salt of dicamba, a compound with herbi-
cidal activity. The primary reference disclosed inter alia the 
substituted ammonium salts of dicamba as herbicides, how-
ever the reference did not specifically teach the claimed 
salt. Secondary references teaching the amine portion of the 
salt were directed to shampoo additives and a byproduct of 
the production of morpholine. The court found there was no 
suggestion to combine these references to arrive at the 
claimed  invention.

WHERE THE TEACHINGS OF THE PRIOR ART 
CONFLICT, THE EXAMINER MUST WEIGH THE 
SUGGESTIVE POWER OF EACH REFERENCE

The test for obviousness is what the combined teachings 
of the references would have suggested to one of ordinary 
skill in the art, and all teachings in the prior art must be 
considered to the extent that they are in analogous arts. 
Where the teachings of two or more prior art references 
conflict, the examiner must weigh the power of each refer-
ence to suggest solutions to one of ordinary skill in the art, 
considering the degree to which one reference might accu-
rately discredit another. In re Young, 927 F.2d 588, 18 
USPQ2d 1089 (Fed. Cir. 1991) (Prior art patent to Carlisle 
disclosed controlling and minimizing bubble oscillation for 
chemical explosives used in marine seismic exploration by 
spacing seismic sources close enough to allow the bubbles 
to intersect before reaching their maximum radius so the 
secondary pressure pulse was reduced. An article published 
several years later by Knudsen opined that the Carlisle 
technique does not yield appreciable improvement in bub-
ble oscillation suppression. However, the article did not test 
the Carlisle technique under comparable conditions 
because Knudsen did not use Carlisle's spacing or seismic 
source. Furthermore, where the Knudsen model most 
closely approximated the patent technique there was a 30% 
reduction of the secondary pressure pulse. On these facts, 
the court found that the Knudsen article would not have 
deterred one of ordinary skill in the art from using the Carl-
isle patent teachings.).

FACT THAT REFERENCES CAN BE COMBINED 
OR MODIFIED IS NOT SUFFICIENT TO ESTAB-
LISH PRIMA FACIE OBVIOUSNESS

The mere fact that references can be combined or modi-
fied does not render the resultant combination obvious 
unless the prior art also suggests the desirability of the 
combination. In re Mills, 916 F.2d 680, 16 USPQ2d 1430 
(Fed. Cir. 1990) (Claims were directed to an apparatus for 
producing an aerated cementitious composition by drawing 
air into the cementitious composition by driving the output 
pump at a capacity greater than the feed rate. The prior art 
reference taught that the feed means can be run at a variable 
speed, however the court found that this does not require 
that the output pump be run at the claimed speed so that air 
is drawn into the mixing chamber and is entrained in the 
ingredients during operation. Although a prior art device 
"may be capable of being modified to run the way the appa-
ratus is claimed, there must be a suggestion or motivation 
in the reference to do so." 916 F.2d at 682, 16 USPQ2d at 
1432.). See also In re Fritch, 972 F.2d 1260, 23 USPQ2d 
1780 (Fed. Cir. 1992) (flexible landscape edging device 
which is conformable to a ground surface of varying slope 
not suggested by combination of prior art references).

FACT THAT THE CLAIMED INVENTION IS 
WITHIN THE CAPABILITIES OF ONE OF ORDI-
NARY SKILL IN THE ART IS NOT SUFFICIENT BY 
ITSELF TO ESTABLISH PRIMA FACIE OBVIOUS-
NESS

A statement that modifications of the prior art to meet 
the claimed invention would have been " `well within the 
ordinary skill of the art at the time the claimed invention 
was made' " because the references relied upon teach that 
all aspects of the claimed invention were individually 
known in the art is not sufficient to establish a prima facie 
case of obviousness without some objective reason to com-
bine the teachings of the references.   Ex parte Levengood, 
28 USPQ2d 1300 (Bd. Pat. App. & Inter. 1993).  >See also 
Al-Site Corp. v. VSI Int'l Inc., 174 F.3d 1308, 50 USPQ2d 
1161 (Fed. Cir. 1999) (The level of skill in the art cannot be 
relied upon to provide the suggestion to combine refer-
ences.).<

THE PROPOSED MODIFICATION CANNOT REN-
DER THE PRIOR ART UNSATISFACTORY FOR ITS 
INTENDED PURPOSE 

If proposed modification would render the prior art 
invention being modified unsatisfactory for its intended 
purpose, then there is no suggestion or motivation to make 
the proposed modification. In re Gordon, 733 F.2d 900, 221 
USPQ 1125 (Fed. Cir. 1984) (Claimed device was a blood 
filter assembly for use during medical procedures wherein 
both the inlet and outlet for the blood were located at the 
bottom end of the filter assembly, and wherein a gas vent 
was present at the top of the filter assembly. The prior art 
reference taught a liquid strainer  for removing dirt and 
water from gasoline and other light oils wherein the inlet 
and outlet were at the top of the device, and wherein a pet-
cock (stopcock) was located at the bottom of the device for 
periodically removing the collected dirt and water. The ref-
erence further taught that the separation is assisted by grav-
ity. The Board concluded the claims were prima facie 
obvious, reasoning that it would have been obvious to turn 
the reference device upside down. The court reversed, find-
ing that if the prior art device was turned upside down it 
would be inoperable for its intended purpose because the 
gasoline to be filtered would be trapped at the top, the 
water and heavier oils sought to be separated would flow 
out of the outlet instead of the purified gasoline, and the 
screen would become clogged.).  

>"Although statements limiting the function or capabil-
ity of a prior art device require fair consideration, simplic-
ity of the prior art is rarely a characteristic that weighs 
against obviousness of a more complicated device with 
added function." In re Dance, 160 F.3d 1339, 1344, 48 
USPQ2d 1635, 1638 (Fed. Cir. 1998)(Court held that 
claimed catheter for removing obstruction in blood vessels 
would have been obvious in view of a first reference which 
taught all of the claimed elements except for a "means for 
recovering fluid and debris" in combination with a second 
reference describing a catheter including that means. The 
court agreed that the first reference, which stressed simplic-
ity of structure and taught emulsification of the debris, did 
not teach away from the addition of a channel for the recov-
ery of the debris.).<

THE PROPOSED MODIFICATION CANNOT 
CHANGE THE PRINCIPLE OF OPERATION OF A 
REFERENCE

If the proposed modification or combination of the prior 
art would change the principle of operation of the prior art 
invention being modified, then the teachings of the refer-
ences are not sufficient to render the claims prima facie 
obvious. In re Ratti, 270 F.2d 810, 123 USPQ 349 (CCPA 
1959) (Claims were directed to an oil seal comprising a 
bore engaging portion with outwardly biased resilient 
spring fingers inserted in a resilient sealing member. The 
primary reference relied upon in a rejection based on a 
combination of references disclosed an oil seal wherein the 
bore engaging portion was reinforced by a cylindrical sheet 
metal casing. Patentee taught the device required rigidity 
for operation, whereas the claimed invention required resil-
iency. The court reversed the rejection holding the "sug-
gested combination of references would require a 
substantial reconstruction and redesign of the elements 
shown in [the primary reference] as well as a change in the 
basic principle under which the [primary reference] con-
struction was designed to operate." 270 F.2d at 813, 123 
USPQ at 352.).

2143.02	Reasonable Expectation of Success 
Is Required 

OBVIOUSNESS REQUIRES ONLY A REASONABLE 
EXPECTATION OF SUCCESS

The prior art can be modified or combined to reject 
claims as prima facie obvious as long as there is a reason-
able expectation of success. In re Merck & Co., Inc., 800 
F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (Claims 
directed to a method of treating depression with amitrip-
tyline (or nontoxic salts thereof) were rejected as prima 
facie obvious over prior art disclosures that amitriptyline is 
a compound known to possess psychotropic properties and 
that imipramine is a structurally similar psychotropic com-
pound known to possess antidepressive properties, in view 
of prior art suggesting the aforementioned compounds 
would be expected to have similar activity because the 
structural difference between the compounds involves a 
known bioisosteric replacement and because a research 
paper comparing the pharmacological properties of these 
two compounds suggested clinical testing of amitriptyline 
as an antidepressant. The court sustained the rejection, 
finding that the teachings of the prior art provide a suffi-
cient basis for a reasonable expectation of success.); Ex 
parte Blanc, 13 USPQ2d 1383 (Bd. Pat. App. & Inter. 
1989) (Claims were directed to a process of sterilizing a 
polyolefinic composition with high-energy radiation in the 
presence of a phenolic polyester antioxidant to inhibit dis-
coloration or degradation of the polyolefin. Appellant 
argued that it is unpredictable whether a particular antioxi-
dant will solve the problem of discoloration or degradation. 
However, the Board found that because the prior art taught 
that appellant's preferred antioxidant is very efficient and 
provides better results compared with other prior art antiox-
idants, there would have been a reasonable expectation of 
success.). 

AT LEAST SOME DEGREE OF PREDICTABILITY 
IS REQUIRED; APPLICANTS MAY PRESENT EVI-
DENCE SHOWING THERE WAS NO REASONABLE 
EXPECTATION OF SUCCESS

Obviousness does not require absolute predictability, 
however, at least some degree of predictability is required. 
Evidence showing there was no reasonable expectation of 
success may support a conclusion of nonobviousness. In re 
Rinehart, 531 F.2d 1048, 189 USPQ 143 (CCPA 1976) 
(Claims directed to a method for the commercial scale pro-
duction of polyesters in the presence of a solvent at superat-
mospheric pressure were rejected as obvious over a 
reference which taught the claimed method at atmospheric 
pressure in view of a reference which taught the claimed 
process except for the presence of a solvent. The court 
reversed, finding there was no reasonable expectation that a 
process combining the prior art steps could be successfully 
scaled up in view of unchallenged evidence showing that 
the prior art processes individually could not be commer-
cially scaled up successfully.). See also Amgen, Inc. v. 
Chugai Pharmaceutical Co., 927 F.2d 1200, 1207-08, 18 
USPQ2d 1016, 1022-23 (Fed. Cir.), cert. denied, 502 U.S. 
856 (1991) (In the context of a biotechnology case, testi-
mony supported the conclusion that the references did not 
show that there was a reasonable expectation of success.);  
In re O'Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673, 1681 
(Fed. Cir. 1988) (The court held the claimed method would 
have been obvious over the prior art relied upon because 
one reference contained a detailed enabling methodology, a 
suggestion to modify the prior art to produce the claimed 
invention, and evidence suggesting the modification would 
be successful.).

PREDICTABILITY IS DETERMINED AT THE TIME 
THE INVENTION WAS MADE

Whether an art is predictable or whether the proposed 
modification or combination of the prior art has a reason-
able expectation of success is determined at the time the 
invention was made. Ex parte Erlich, 3 USPQ2d 1011 (Bd. 
Pat. App. & Inter. 1986) (Although an earlier case reversed 
a rejection because of unpredictability in the field of mono-
clonal antibodies, the court found "in this case at the time 
this invention was made, one of ordinary skill in the art 
would have been motivated to produce monoclonal anti-
bodies specific for human fibroplast interferon using the 
method of [the prior art] with a reasonable expectation of 
success." 3 USPQ2d at 1016 (emphasis in original).). 

2143.03	All Claim Limitations Must Be 
Taught or Suggested 

To establish prima facie obviousness of a claimed inven-
tion, all the claim limitations must be taught or suggested 
by the prior art. In re Royka, 490 F.2d 981, 180 USPQ 580 
(CCPA 1974). "All words in a claim must be considered in 
judging the patentability of that claim against the prior art." 
In re Wilson, 424 F.2d 1382, 1385,  165 USPQ 494, 496 
(CCPA 1970). If an independent claim is nonobvious under  
35 U.S.C. 103, then any claim depending therefrom is non-
obvious. In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. 
Cir. 1988).

INDEFINITE LIMITATIONS MUST BE CONSID-
ERED

A claim limitation which is considered indefinite cannot 
be disregarded. If a claim is subject to more than one inter-
pretation, at least one of which would render the claim 
unpatentable over the prior art, the examiner should reject 
the claim as indefinite under  35 U.S.C. 112, second para-
graph (see  MPEP ? 706.03(d)) and should reject the claim 
over the prior art based on the interpretation of the claim 
that renders the prior art applicable. Ex parte Ionescu, 222 
USPQ 537 (Bd. Pat. App. & Inter. 1984) (Claims on appeal 
were rejected on indefiniteness grounds only; the rejection 
was reversed and the case remanded to the examiner for 
consideration of pertinent prior art.). Compare In re Wilson, 
424 F.2d 1382, 165 USPQ 494 (CCPA 1970) (if no reason-
ably definite meaning can be ascribed to certain claim lan-
guage, the claim is indefinite, not obvious) and In re Steele, 
305 F.2d 859,134 USPQ 292 (CCPA 1962) (it is improper 
to rely on speculative assumptions regarding the meaning 
of a claim and then base a rejection under 35 U.S.C. 103 on 
these assumptions).

LIMITATIONS WHICH DO NOT FIND SUPPORT IN 
THE ORIGINAL SPECIFICATION MUST BE CON-
SIDERED

When evaluating claims for obviousness under 
35 U.S.C. 103, all the limitations of the claims must be 
considered and given weight, including limitations which 
do not find support in the specification as originally filed 
(i.e., new matter). Ex parte Grasselli, 231 USPQ 393 (Bd. 
App. 1983) aff'd mem. 738 F.2d 453 (Fed. Cir. 1984) 
(Claim to a catalyst expressly excluded the presence of sul-
fur, halogen, uranium, and a combination of vanadium and 
phosphorous. Although the negative limitations excluding 
these elements did not appear in the specification as filed, it 
was error to disregard these limitations when determining 
whether the claimed invention would have been obvious in 
view of the prior art.).

2144	Sources of Rationale Supporting a 
Rejection Under 35 U.S.C. 103 

RATIONALE MAY BE IN A REFERENCE, OR REA-
SONED FROM COMMON KNOWLEDGE IN THE 
ART, SCIENTIFIC PRINCIPLES, ART- RECOG-
NIZED EQUIVALENTS, OR LEGAL PRECEDENT

The rationale to modify or combine the prior art does not 
have to be expressly stated in the prior art; the rationale 
may be expressly or impliedly contained in the prior art or 
it may be reasoned from knowledge generally available to 
one of ordinary skill in the art, established scientific princi-
ples, or legal precedent established by prior case law. In re 
Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988); In 
re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992). 
See also In re Eli Lilly & Co., 902 F.2d 943, 14 USPQ2d 
1741 (Fed. Cir. 1990) (discussion of reliance on legal pre-
cedent); In re Nilssen, 851 F.2d 1401, 1403, 7 USPQ2d 
1500, 1502 (Fed. Cir. 1988) (references do not have to 
explicitly suggest combining teachings); Ex parte Clapp, 
227 USPQ 972 (Bd. Pat. App. & Inter. 1985) (examiner 
must present convincing line of reasoning supporting rejec-
tion); and Ex parte Levengood, 28 USPQ2d 1300 (Bd. Pat. 
App. & Inter. 1993) (reliance on logic and sound scientific 
reasoning). 

THE EXPECTATION OF SOME ADVANTAGE IS 
THE STRONGEST RATIONALE FOR COMBINING 
REFERENCES

The strongest rationale for combining references is a rec-
ognition, expressly or impliedly in the prior art or drawn 
from a convincing line of reasoning based on established 
scientific principles or legal precedent, that some advantage 
or expected beneficial result would have been produced by 
their combination. In re Sernaker, 702 F.2d 989, 994-95, 
217 USPQ 1, 5-6 (Fed. Cir. 1983).

LEGAL PRECEDENT CAN PROVIDE THE RATIO-
NALE SUPPORTING OBVIOUSNESS ONLY IF THE 
FACTS IN THE CASE ARE SUFFICIENTLY SIMI-
LAR TO THOSE IN THE APPLICATION

The examiner must apply the law consistently to each 
application after considering all the relevant facts. If the 
facts in a prior legal decision are sufficiently similar to 
those in an application under examination, the examiner 
may use the rationale used by the court. If the applicant has 
demonstrated the criticality of a specific limitation, it 
would not be appropriate to rely solely on case law as the 
rationale to support an obviousness rejection. "The value of 
the exceedingly large body of precedent wherein our prede-
cessor courts and this court have applied the law of obvi-
ousness to particular facts, is that there has been built a 
wide spectrum of illustrations and accompanying reason-
ing, that have been melded into a fairly consistent applica-
tion of law to a great variety of facts." In re Eli Lilly & Co., 
902 F.2d 943, 14 USPQ2d 1741 (Fed. Cir. 1990).

RATIONALE DIFFERENT FROM APPLICANT'S IS 
PERMISSIBLE

The reason or motivation to modify the reference may 
often suggest what the inventor has done, but for a different 
purpose or to solve a different problem. It is not necessary 
that the prior art suggest the combination to achieve the 
same advantage or result discovered by applicant. In re 
Linter, 458 F.2d 1013, 173 USPQ 560 (CCPA 1972) (dis-
cussed below); In re Dillon, 919 F.2d 688, 16 USPQ2d 
1897 (Fed. Cir. 1990), cert. denied, 500 U.S. 904 (1991) 
(discussed below). Although Ex parte Levengood, 28 
USPQ2d 1300, 1302 (Bd. Pat. App. & Inter. 1993) states 
that obviousness cannot be established by combining refer-
ences "without also providing evidence of the motivating 
force which would impel one skilled in the art to do what 
the patent applicant has done" (emphasis added), reading 
the quotation in context it is clear that while there must be 
motivation to make the claimed invention, there is no 
requirement that the prior art provide the same reason as 
the applicant to make the claimed invention.

In In re Linter the claimed invention was a laundry com-
position consisting essentially of a dispersant, cationic fab-
ric softener, sugar, sequestering phosphate, and brightener 
in specified proportions. The claims were rejected over the 
combination of a primary reference which taught all 
the claim limitations except for the presence of sugar, and 
secondary references which taught the addition of sugar as 
a filler or weighting agent in compositions containing cat-
ionic fabric softeners. Appellant argued that in the claimed 
invention, the sugar is responsible for the compatibility of 
the cationic softener with the other detergent components. 
The court sustained  the rejection, stating "The fact that 
appellant uses sugar for a different purpose does not alter 
the conclusion that its use in a prior art composition would 
be [sic, would have been] prima facie obvious from the 
purpose disclosed in the references." 173 USPQ at 562.

In In re Dillon, applicant claimed a composition com-
prising a hydrocarbon fuel and a sufficient amount of a 
tetra-orthoester of a specified formula to reduce the particu-
late emissions from the combustion of the fuel. The claims 
were rejected as obvious over a reference which taught 
hydrocarbon fuel compositions containing tri-orthoesters 
for dewatering fuels, in combination with a reference teach-
ing the equivalence of tri-orthoesters and tetra-orthoesters 
as water scavengers in hydraulic (nonhydrocarbon) fluids. 
The Board affirmed the rejection finding "there was a `rea-
sonable expectation' that the tri- and tetra-orthoester fuel 
compositions would have similar properties based on `close 
structural and chemical similarity' between the tri- and 
tetra-orthoesters and the fact that both the prior art and Dil-
lon use these compounds `as fuel additives'." 919 F.2d at 
692, 16 USPQ2d at 1900. The court held "it is not neces-
sary in order to establish a prima facie case of obviousness 
. . . that there be a suggestion or expectation from the prior 
art that the claimed [invention] will have the same or a sim-
ilar utility as one newly discovered by applicant," and con-
cluded that here a prima facie case was established because 
"[t]he art provided the motivation to make the claimed 
compositions in the expectation that they would have simi-
lar properties." 919 F.2d at 693, 16 USPQ2d at 1901 
(emphasis in original).

See  MPEP ? 2145, paragraph II for case law pertaining 
to the presence of additional advantages or latent properties 
not recognized in the prior art.

2144.01	Implicit Disclosure 

"[I]n considering the disclosure of a reference, it is 
proper to take into account not only specific teachings of 
the reference but also the inferences which one skilled in 
the art would reasonably be expected to draw therefrom." 
In re Preda, 401 F.2d 825, 826, 159 USPQ 342, 344 (CCPA 
1968) (A process for catalytically producing carbon disul-
fide by reacting sulfur vapor and methane in the presence 
of charcoal at a temperature of "about 750-830C" was 
found to be met by a reference which expressly taught the 
same process at 700C because the reference recognized the 
possibility of using temperatures greater than 750C. The 
reference disclosed that catalytic processes for converting 
methane with sulfur vapors into carbon disulfide at temper-
atures greater than 750C (albeit without charcoal) was 
known, and that 700C was "much lower than had previ-
ously proved feasible."); In re Lamberti, 545 F.2d 747, 750, 
192 USPQ 278, 280 (CCPA 1976) (Reference disclosure of 
a compound where the R-S-R?  portion has "at least one 
methylene group attached to the sulfur atom" implies that 
the other R group attached to the sulfur atom can be other 
than methylene and therefore suggests asymmetric dialkyl 
moieties.).

2144.02	Reliance on Scientific Theory 

The rationale to support a rejection under  35 U.S.C. 103 
may rely on logic and sound scientific principle. In re Soli, 
317 F.2d 941, 137 USPQ 797 (CCPA 1963). However, 
when an examiner relies on a scientific theory, evidentiary 
support for the existence and meaning of that theory must 
be provided. In re Grose, 592 F.2d 1161, 201 USPQ 57 
(CCPA 1979) (Court held that different crystal forms of 
zeolites would not have been structurally obvious one from 
the other because there was no chemical theory supporting 
such a conclusion. The known chemical relationship 
between structurally similar compounds (homologs, ana-
logs, isomers) did not support a finding of prima facie 
obviousness of claimed zeolite over the prior art because a 
zeolite is not a compound but a mixture of compounds 
related to each other by a particular crystal structure.). 
Although the theoretical mechanism of an invention may 
be explained by logic and sound scientific reasoning, this 
fact does not support an obviousness determination unless 
logic and scientific reasoning would have led one of ordi-
nary skill in the art to make the claimed invention. Ex parte 
Levengood, 28 USPQ2d 1300 (Bd. Pat. App. & Inter. 
1993).

2144.03	Reliance on Common Knowledge in 
the Art or "Well Known" Prior Art 

The rationale supporting an obviousness rejection may 
be based on common knowledge in the art or "well-known" 
prior art. The examiner may take official notice  of facts 
outside of the record which are capable of instant and 
unquestionable demonstration as being "well- known"  in 
the art. In re Ahlert, 424 F.2d 1088, 1091, 165  USPQ 418, 
420 (CCPA 1970) (Board properly took judicial notice that 
"it is common practice to postheat a weld after the welding 
operation is completed" and that "it is old to adjust the 
intensity of a flame in accordance with the heat require-
ments."). See also In re Seifreid, 407 F.2d 897, 160 USPQ 
804 (CCPA 1969) (Examiner's statement that polyethylene 
terephthalate films are commonly known to be shrinkable 
is a statement of common knowledge in the art, supported 
by the references of record.).

If justified, the examiner should not be obliged to spend 
time to produce documentary proof. If the knowledge is of 
such notorious character that official notice can be taken, it 
is sufficient so to state. In re Malcolm, 129 F.2d 529, 54 
USPQ 235 (CCPA 1942). If the applicant traverses such an 
assertion the examiner should cite a reference in support of 
his or her position.

When a rejection is based on facts within the personal 
knowledge of the examiner, the data should be stated as 
specifically as possible, and the facts must be supported, 
when called for by the applicant, by an affidavit from the 
examiner. Such an affidavit is subject to contradiction or 
explanation by the affidavits of the applicant and other per-
sons. See  37 CFR 1.104(d)(2).

Applicant must seasonably challenge well known state-
ments and statements based on personal knowledge when 
they are made by the Board of Patent Appeals and Interfer-
ences. In re Selmi, 156 F.2d 96, 70 USPQ 197 (CCPA 
1946); In re Fischer, 125 F.2d 725, 52 USPQ 473 (CCPA 
1942). See also In re Boon, 439 F.2d 724, 169 USPQ 231 
(CCPA 1971) (a challenge to the taking of judicial notice 
must contain adequate information or argument to create on 
its face a reasonable doubt regarding the circumstances jus-
tifying the judicial notice).

For further views on official notice, see In re Ahlert, 424 
F.2d 1088, 1091, 165 USPQ 418, 420-421 (CCPA 1970) 
("[A]ssertions of technical facts in areas of esoteric tech-
nology must always be supported by citation of some refer-
ence work" and "allegations concerning specific 
`knowledge' of the prior art, which might be peculiar to a 
particular art should also be supported." Furthermore the 
applicant must be given the opportunity to challenge the 
correctness of such assertions and allegations. "The facts so 
noticed serve to `fill the gaps' which might exist in the evi-
dentiary showing" and should not comprise the principle 
evidence upon which a rejection is based.). See also In re 
Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 1971) (scien-
tific journal references were not used as a basis for taking 
judicial notice that controverted phrases were art-recog-
nized because the court was not sure that the meaning of 
the term at issue was indisputable among reasonable men); 
and In re Eynde, 480 F.2d 1364, 1370,  178 USPQ 470, 474 
(CCPA 1973) ("The facts constituting the state of the art are 
normally subject to the possibility of rational disagreement 
among reasonable men and are not amenable to the taking 
of [judicial] notice.").

If applicant does not seasonably traverse the well known 
statement during examination, then the object of the well 
known statement is taken to be admitted prior art. In re 
Chevenard, 139 F.2d 71, 60 USPQ 239 (CCPA 1943). A 
seasonable challenge constitutes a demand for evidence 
made as soon as practicable during prosecution. Thus, 
applicant is charged with rebutting the well known state-
ment in the next reply after the Office action in which the 
well known statement was made. This is necessary because 
the examiner must be given the opportunity to provide evi-
dence in the next Office action or explain why no evidence 
is required. If the examiner adds a reference to the rejection 
in the next action after applicant's rebuttal, the newly cited 
reference, if it is added merely as evidence of the prior well 
known statement, does not result in a new issue and thus 
the action can potentially be made final. If no amendments 
are made to the claims, the examiner must not rely on any 
other teachings in the reference if the rejection is made 
final.

2144.04	Legal Precedent as Source of 
Supporting Rationale  [R-1]

As discussed in MPEP ? 2144, if the facts in a prior legal 
decision are sufficiently similar to those in an application 
under examination, the examiner may use the rationale 
used by the court. Examples directed to various common 
practices which the court has held normally require only 
ordinary skill in the art and hence are considered routine 
expedients are discussed below. If the applicant has demon-
strated the criticality of a specific limitation, it would not 
be appropriate to rely solely on case law as the rationale to 
support an obviousness rejection.

I.	AESTHETIC DESIGN CHANGES

In re Seid, 161 F.2d 229, 73 USPQ 431 (CCPA 1947) 
(Claim was directed to an advertising display device com-
prising a bottle and a hollow member in the shape of a 
human figure from the waist up which was adapted to  fit 
over and cover the neck of the bottle, wherein the hollow 
member and the bottle together give the impression of a 
human body. Appellant argued that certain limitations in 
the upper part of the body, including the arrangement of the 
arms, were not taught by the prior art. The court found that 
matters relating to ornamentation only which have no 
mechanical function cannot be relied upon to patentably 
distinguish the claimed invention from the prior art.). But 
see >In re Dembiczak 175 F.3d 994, 50 USPQ2d 1614 
(Fed. Cir. 1999)(The claims of a utility application, drawn 
to a generally round, orange plastic trash bag with a jack-o-
lantern face, were rejected under 35 U.S.C. 103. However, 
the court reversed the rejection for lack of motivation to 
combine conventional trash bags with a reference showing 
a jack-o-lantern face on an orange paper bag stuffed with 
newspapers.);< Ex parte Hilton, 148 USPQ 356 (Bd. App. 
1965) (Claims were directed to fried potato chips with a 
specified moisture and fat content, whereas the prior art 
was directed to french fries having a higher moisture con-
tent. While recognizing that in some cases the particular 
shape of a product is of no patentable significance, the 
Board held in this case the shape (chips) is important 
because it results in a product which is distinct from the ref-
erence product (french fries).). 

II.	ELIMINATION OF A STEP OR AN ELEMENT 
AND ITS FUNCTION

A.	Omission of an Element and Its Function Is 
Obvious If the Function of the Element Is Not 
Desired

Ex parte Wu, 10 USPQ 2031 (Bd. Pat. App. & Inter. 
1989) (Claims at issue were directed to a method for inhib-
iting corrosion on metal surfaces using a composition con-
sisting of epoxy resin, petroleum sulfonate, and 
hydrocarbon diluent. The claims were rejected over a pri-
mary reference which disclosed an anticorrosion composi-
tion of epoxy resin, hydrocarbon diluent, and polybasic 
acid salts wherein said salts were taught to be beneficial 
when employed in a freshwater environment, in view of 
secondary references which clearly suggested the addition 
of petroleum sulfonate to corrosion inhibiting composi-
tions. The Board affirmed the rejection, holding that it 
would have been obvious to omit the polybasic acid salts of 
the primary reference where the function attributed to such 
salt is not desired or required, such as in compositions for 
providing corrosion resistance in environments which do 
not encounter fresh water.). See also In re Larson, 340 F.2d 
965, 144 USPQ 347 (CCPA 1965) (Omission of additional 
framework and axle which served to increase the cargo car-
rying capacity of prior art mobile fluid carrying unit would 
have been obvious if this feature was not desired.); and In 
re Kuhle, 526 F.2d 553, 188 USPQ 7 (CCPA 1975) (delet-
ing a prior art switch member and thereby eliminating its 
function was an obvious expedient).

B.	Omission of an Element with Retention of the Ele-
ment's Function Is an Indicia of Unobviousness

Note that the omission of an element and retention of its 
function is an indicia of unobviousness. In re Edge, 359 
F.2d 896, 149 USPQ 556 (CCPA 1966) (Claims at issue 
were directed to a printed sheet having a thin layer of eras-
able metal bonded directly to the sheet wherein said thin 
layer obscured the original print until removal by erasure. 
The prior art disclosed a similar printed sheet which further 
comprised an intermediate transparent and erasure-proof 
protecting layer which prevented erasure of the printing 
when the top layer was erased. The claims were found 
unobvious over the prior art because the although the trans-
parent layer of the prior art was eliminated, the function of 
the transparent layer was retained since appellant's metal 
layer could be erased without erasing the printed indicia.).

III.	AUTOMATING A MANUAL ACTIVITY 

In re Venner, 262 F.2d 91, 95, 120 USPQ 193, 194 
(CCPA 1958) (Appellant argued that claims to a permanent 
mold casting apparatus for molding trunk pistons were 
allowable over the prior art because the claimed invention 
combined "old permanent-mold structures together with a 
timer and solenoid which automatically actuates the known 
pressure valve system to release the inner core after a pre-
determined time has elapsed." The court held that broadly 
providing an automatic or mechanical means to replace a 
manual activity which accomplished the same result is not 
sufficient to distinguish over the prior art.).

IV.	CHANGES IN SIZE, SHAPE, OR SEQUENCE 
OF ADDING INGREDIENTS 

A.	Changes in Size/Proportion

In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955) 
(Claims directed to a lumber package "of appreciable size 
and weight requiring handling by a lift truck" where held 
unpatentable over prior art lumber packages which could 
be lifted by hand because limitations relating to the size of 
the package were not sufficient to patentably distinguish 
over the prior art.); In re Rinehart, 531 F.2d 1048, 189 
USPQ 143 (CCPA 1976) ("mere scaling up of a prior art 
process capable of being scaled up, if such were the case, 
would not establish patentability in a claim to an old pro-
cess so scaled." 531 F.2d  at 1053, 189 USPQ at 148.).

In Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 
USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 
USPQ 232 (1984), the Federal Circuit held that, where the 
only difference between the prior art and the claims was a 
recitation of relative dimensions of the claimed device and 
a device having the claimed relative dimensions would not 
perform differently than the prior art device, the claimed 
device was not patentably distinct from the prior art device.

B.	Changes in Shape

In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966) 
(The court held that the configuration of the claimed dis-
posable plastic nursing container was a matter of 
*>choice< which a person of ordinary skill in the art would 
have found obvious absent persuasive evidence that the 
particular configuration of the claimed container was sig-
nificant.).

C.	Changes in Sequence of Adding Ingredients

Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959) (Prior 
art reference disclosing a process of making a laminated 
sheet wherein a base sheet is first coated with a metallic 
film and thereafter impregnated with a thermosetting mate-
rial was held to render prima facie obvious claims directed 
to a process of making a laminated sheet by reversing the 
order of the prior art process steps.). See also In re 
Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) (selec-
tion of any order of performing process steps is prima facie 
obvious in the absence of new or unexpected results); In re 
Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930) (Selection 
of any order of mixing ingredients is prima facie obvious.). 

V.	MAKING PORTABLE, INTEGRAL, SEPARA-
BLE, ADJUSTABLE, OR CONTINUOUS

A.	Making Portable

In re Lindberg, 194 F.2d 732, 93 USPQ 23 (CCPA 1952) 
(Fact that a claimed device is portable or movable is not 
sufficient by itself to patentably distinguish over an other-
wise old device unless there are new or unexpected 
results.).

B.	Making Integral

In re Larson, 340 F.2d 965, 968, 144 USPQ 347, 349 
(CCPA 1965) (A claim to a fluid transporting vehicle was 
rejected as obvious over a prior art reference which differed 
from the prior art in claiming a brake drum integral with a 
clamping means, whereas the brake disc and clamp of the 
prior art comprise several parts rigidly secured together as a 
single unit. The court affirmed the rejection holding, 
among other reasons, "that the use of a one piece construc-
tion instead of the structure disclosed in [the prior art] 
would be merely a matter of obvious engineering choice."); 
but see Schenck v. Nortron Corp., 713 F.2d 782, 218 USPQ 
698 (Fed. Cir. 1983) (Claims were directed to a vibratory 
testing machine (a hard-bearing wheel balancer) compris-
ing a holding structure, a base structure, and a supporting 
means which form "a single integral and gaplessly continu-
ous piece." Nortron argued that the invention is just making 
integral what had been made in four bolted pieces. The 
court found this argument unpersuasive and held that the 
claims were patentable because the prior art perceived a 
need for mechanisms to dampen resonance, whereas the 
inventor eliminated the need for dampening via the one-
piece gapless support structure, showing insight that was 
contrary to the understandings and expectations of the art.).

C.	Making Separable

In re Dulberg, 289 F.2d 522, 523, 129 USPQ 348, 349 
(CCPA 1961) (The claimed structure, a lipstick holder with 
a removable cap, was fully met by the prior art except that 
in the prior art the cap is "press fitted" and therefore not 
manually removable. The court held that "if it were consid-
ered desirable for any reason to obtain  access to the end of 
[the prior art's] holder to which the cap is applied, it would 
be obvious to make the cap removable for that purpose."). 

D.	Making Adjustable

In re Stevens, 212 F.2d 197, 101 USPQ 284 (CCPA 
1954) (Claims were directed to a handle for a fishing rod 
wherein the handle has a longitudinally adjustable finger 
hook, and the hand grip of the handle connects with the 
body portion by means of a universal joint. The court held 
that adjustability, where needed, is not a patentable 
advance, and because there was an art-recognized need for 
adjustment in a fishing rod, the substitution of a universal 
joint for the single pivot of the prior art would have been 
obvious.).

E.	Making Continuous 

In re Dilnot, 319 F.2d 188, 138 USPQ 248 (CCPA 1963) 
(Claim directed to a method of producing a cementitious 
structure wherein a stable air foam is introduced into a 
slurry of cementitious material differed from the prior art 
only in requiring the addition of the foam to be continuous. 
The court held the claimed continuous operation would 
have been obvious in light of the batch process of the prior 
art.).

VI.	REVERSAL, DUPLICATION, OR REAR 
RANGEMENT OF PARTS 

A.	Reversal of Parts

In re Gazda, 219 F.2d 449, 104 USPQ 400 (CCPA 1955) 
(Prior art disclosed a clock fixed to the stationary steering 
wheel column of an automobile while the gear for winding 
the clock moves with steering wheel; mere reversal of such 
movement, so the clock moves with wheel, was held to be 
an obvious expedient.).

B.	Duplication of Parts

In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960) 
(Claims at issue were directed to a water-tight masonry 
structure wherein a water seal of flexible material fills the 
joints which form between adjacent pours of concrete. The 
claimed water seal has a "web" which lies perpendicular to 
the workface and in the joint, and a plurality of "ribs" 
which are parallel to the workface, forming the following 
shape:

The prior art disclosed a flexible water stop for preventing 
passage of water between masses of concrete in the shape 
of a plus sign (+).  Although the reference did not disclose a 
plurality of ribs, the court held that mere duplication of 
parts has no patentable significance unless a new and unex-
pected result is produced.).

C.	Rearrangement of Parts

In re Japikse, 181 F.2d 1019, 86 USPQ 70 (CCPA 1950) 
(Claims to a hydraulic power press which read on the prior 
art except with regard to the position of the starting switch 
were held unpatentable because shifting the position of the 
starting switch would not have modified the operation of 
the device.); In re Kuhle, 526 F.2d 553, 188 USPQ 7 
(CCPA 1975) (the particular placement of a contact in a 
conductivity measuring device was held to be an obvious 
matter of design choice). However, "The mere fact that a 
worker in the art could rearrange the parts of the reference 
device to meet the terms of the claims on appeal is not by 
itself sufficient to support a finding of obviousness. The 
prior art must provide a motivation or reason for the worker 
in the art, without the benefit of appellant's specification, to 
make the necessary changes in the reference device." Ex 
parte Chicago Rawhide Mfg. Co., 223 USPQ 351, 353 (Bd. 
Pat. App. & Inter. 1984).

VII.	PURIFYING AN OLD PRODUCT

Pure materials are novel vis-a-vis less pure or impure 
materials because there is a difference between pure and 
impure materials. Therefore, the issue is whether claims to 
a pure material are unobvious over the prior art. In re Berg-
strom, 427 F.2d 1394, 166 USPQ 256 (CCPA 1970). Purer 
forms of known products may be patentable, but the mere 
purity of a product, by itself, does not render the product 
unobvious. Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. App. 
& Inter. 1989).

Factors to be considered in determining whether a puri-
fied form of an old product is obvious over the prior art 
include whether the claimed chemical compound or com-
position has the same utility as closely related materials in 
the prior art, and whether the prior art suggests the particu-
lar form or structure of the claimed material or suitable 
methods of obtaining that form or structure. In re Cofer, 
354 F.2d 664, 148 USPQ 268 (CCPA 1966) (Claims to the 
free-flowing crystalline form of a compound were held 
unobvious over references disclosing the viscous liquid 
form of the same compound because the prior art of record 
did not suggest the claimed compound in crystalline form 
or how to obtain such crystals.). 

See also Ex parte Stern, 13 USPQ2d 1379 (Bd. Pat. App. 
& Inter. 1987) (Claims to interleukin 2 (a protein with a 
molecular weight of over 12,000) purified to homogeneity 
were held unpatentable over references which recognized 
the desirability of purifying interleukin 2 to homogeneity in 
a view of a reference which taught a method of purifying 
proteins having molecular weights in excess of 12,000 to 
homogeneity wherein the prior art method was similar to 
the method disclosed by appellant for purifying interleukin 
2.). 

Compare   Ex parte Gray, 10 USPQ2d 1922 (Bd. Pat. 
App. & Inter. 1989) (Claims were directed to human nerve 
growth factor b-NGF free from other proteins of  human 
origin, and the specification disclosed making the claimed 
factor through the use of recombinant DNA technology. 
The claims were rejected as prima facie obvious in view of 
two references disclosing b-NGF isolated from human pla-
cental tissue. The Board applied case law pertinent to prod-
uct-by-process claims, reasoning that the prior art factor 
appeared to differ from the claimed factor only in the 
method of obtaining the factor. The Board held that the bur-
den of persuasion was on appellant to show that the 
claimed product exhibited unexpected properties compared 
with that of the prior art. The Board further noted that "no 
objective evidence has been provided establishing that no 
method was known to those skilled in this field whereby 
the claimed material might have been synthesized." 10 
USPQ2d at 1926.).

2144.05	Obviousness of Ranges 

See  MPEP ? 2131.03 for case law pertaining to rejec-
tions based on the anticipation of ranges under 35 U.S.C. 
102 and  35 U.S.C. 102/103.

I.	OVERLAP OF RANGES

In the case where the claimed ranges "overlap or lie 
inside ranges disclosed by the prior art" a prima facie case 
of obviousness exists. In re Wertheim, 541 F.2d 257, 191 
USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 
USPQ2d 1934 (Fed. Cir. 1990) (The prior art taught carbon 
monoxide concentrations of "about 1-5%" while the claim 
was limited to "more than 5%." The court held that "about 
1-5%" allowed for concentrations slightly above 5% thus 
the ranges overlapped.); In re Geisler, 116 F.3d 1465, 1469-
71, 43 USPQ2d 1362, 1365-66  (Fed. Cir. 1997) (Claim 
reciting thickness of a protective layer as falling within a 
range of "50 to 100 Angstroms" considered prima facie 
obvious in view of prior art reference teaching that "for 
suitable protection, the thickness of the protective layer 
should be not less than about 10 nm [i.e., 100 Angstroms]."  
The court stated that "by stating that `suitable protection' is 
provided if the protective layer is `about' 100 Angstroms 
thick, [the prior art reference] directly teaches the use of a 
thickness within [applicant's] claimed range."). Similarly, a 
prima facie case of obviousness exists where the claimed 
ranges and prior art ranges do not overlap but are close 
enough that one skilled in the art would have expected 
them to have the same properties. Titanium Metals Corp. of 
America v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 
1985) (Court held as proper a rejection of a claim directed 
to an alloy of "having 0.8% nickel, 0.3% molybdenum, up 
to 0.1% iron, balance titanium" as obvious over a reference 
disclosing alloys of 0.75% nickel, 0.25% molybdenum, 
balance titanium and 0.94% nickel, 0.31% molybdenum, 
balance titanium.). 

II.	OPTIMIZATION OF RANGES

A.	Optimization Within Prior Art Conditions or 
Through Routine Experimentation

Generally, differences in concentration or temperature 
will not support the patentability of subject matter encom-
passed by the prior art unless there is evidence indicating 
such concentration or temperature is critical. "[W]here the 
general conditions of a claim are disclosed in the prior art, 
it is not inventive to discover the optimum or workable 
ranges by routine experimentation." In re Aller, 220 F.2d 
454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed pro-
cess which was performed at a temperature between 40C 
and 80C and an acid concentration between 25 and 70% 
was held to be prima facie obvious over a reference process 
which differed from the claims only in that the reference 
process was performed at a temperature of 100C and an 
acid concentration of 10%.). See also In re Hoeschele, 406 
F.2d 1403, 160 USPQ 809 (CCPA 1969) (Claimed elasto-
meric polyurethanes which fell within the broad scope of 
the references were held to be unpatentable thereover 
because, among other reasons, there was no evidence of the 
criticality of the claimed ranges of molecular weight or 
molar proportions.). For more recent cases applying this 
principle, see Merck & Co. Inc. v. Biocraft Laboratories 
Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. 
denied, 493 U.S. 975 (1989);   In re Kulling, 897 F.2d 1147, 
14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 
F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997).

B.	Only Result-effective Variables Can Be Optimized

A particular parameter must first be recognized as a 
result-effective variable, i.e., a variable which achieves a 
recognized result, before the determination of the optimum 
or workable ranges of said variable might be characterized 
as routine experimentation. In re Antonie, 559 F.2d 618, 
195 USPQ 6 (CCPA 1977) (The claimed wastewater treat-
ment device had a tank volume to contractor area of 0.12 
gal./sq. ft. The prior art did not recognize that treatment 
capacity is a function of the tank volume to contractor ratio, 
and therefore the parameter optimized was not recognized 
in the art to be a result- effective variable.). See also In re 
Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980) (prior 
art suggested proportional balancing to achieve desired 
results in the formation of an alloy).

III.	REBUTTAL OF PRIMA FACIE CASE OF 
OBVIOUSNESS

Applicants can rebut a prima facie case of obviousness 
based on overlapping ranges by showing the criticality of 
the claimed range. "The law is replete with cases in which 
the difference between the claimed invention and the prior 
art is some range or other variable within the claims. . . . In 
such a situation, the applicant must show that the particular 
range is critical, generally by showing that the claimed 
range achieves unexpected results relative to the prior art 
range." In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 
(Fed. Cir. 1990). See  MPEP ? 716.02 - ? 716.02(g) for a 
discussion of criticality and unexpected results. 

A prima facie case of obviousness may also be rebutted 
by showing that the art, in any material respect, teaches 
away from the claimed invention. In re Geisler, 116 F.3d 
1465, 1471, 43 USPQ2d 1362, 1366  (Fed. Cir. 1997) 
(Applicant argued that the prior art taught away from use of 
a protective layer for a reflective article having a thickness 
within the claimed range of "50 to 100 Angstroms." Specif-
ically, a patent to Zehender, which was relied upon to reject 
applicant's claim, included a statement that the thickness of 
the protective layer "should be not less than about [100 
Angstroms]."  The court held that the patent did not teach 
away from the claimed invention.  "Zehender suggests that 
there are benefits to be derived from keeping the protective 
layer as thin as possible, consistent with achieving adequate 
protection.  A thinner coating reduces light absorption and 
minimizes manufacturing time and expense. Thus, while 
Zehender expresses a preference for a thicker protective 
layer of 200-300 Angstroms, at the same time it provides 
the motivation for one of ordinary skill in the art to focus 
on thickness levels at the bottom of Zehender's `suitable' 
range- about 100 Angstroms- and to explore thickness lev-
els below that range.  The statement in Zehender that `[i]n 
general, the thickness of the protective layer should be not 
less than about [100 Angstroms]' falls far short of the kind 
of teaching that would discourage one of skill in the art 
from fabricating a protective layer of 100 Angstroms or 
less. [W]e are therefore `not convinced that there was a suf-
ficient teaching away in the art to overcome [the] strong 
case of obviousness' made out by Zehender.").  See  MPEP 
?  2145, paragraph X.D., for a discussion of "teaching 
away" references. 

2144.06	Art Recognized Equivalence for the 
Same Purpose 

COMBINING EQUIVALENTS KNOWN FOR THE 
SAME PURPOSE

"It is prima facie obvious to combine two compositions 
each of which is taught by the prior art to be useful for the 
same purpose, in order to form a third composition to be 
used for the very same purpose. . . . [T]he idea of combin-
ing them flows logically from their having been individu-
ally taught in the prior art." In re Kerkhoven, 626 F.2d 846, 
850, 205 USPQ 1069, 1072 (CCPA 1980) (citations omit-
ted) (Claims to a process of preparing a spray-dried deter-
gent by mixing together two conventional spray-dried 
detergents were held to be prima facie obvious.). See also 
In re Crockett, 279 F.2d 274, 126 USPQ 186 (CCPA 1960) 
(Claims directed to a method and material for treating cast 
iron using a mixture comprising calcium carbide and mag-
nesium oxide were held unpatentable over prior art disclo-
sures that the aforementioned components individually 
promote the formation of a nodular structure in cast iron.); 
and Ex parte Quadranti, 25 USPQ2d 1071 (Bd. Pat. App. 
& Inter. 1992) (mixture of two known herbicides held 
prima facie obvious). But see In re Geiger, 815 F.2d 686, 2 
USPQ2d 1276 (Fed. Cir. 1987) ("Based upon the prior art 
and the fact that each of the three components of the com-
position used in the claimed method is conventionally 
employed in the art for treating cooling water systems, the 
board held that it would have been prima facie obvious, 
within the meaning of 35 U.S.C. 103, to employ these com-
ponents in combination for their known functions and to 
optimize the amount of each additive.... Appellant argues ... 
hindsight reconstruction or at best, ... `obvious to try'.... We 
agree with appellant.").

SUBSTITUTING EQUIVALENTS KNOWN FOR 
THE SAME PURPOSE

In order to rely on equivalence as a rationale supporting 
an obviousness rejection, the equivalency must be recog-
nized in the prior art, and cannot be based on applicant's 
disclosure or the mere fact that the components at issue are 
functional or mechanical equivalents. In re Ruff, 256 F.2d 
590, 118 USPQ 340 (CCPA 1958) (The mere fact that com-
ponents are claimed as members of a Markush group can-
not be relied upon to establish the equivalency of these 
components. However, an applicant's express recognition 
of an art-recognized or obvious equivalent may be used to 
refute an argument that such equivalency does not exist.); 
In re Scott, 323 F.2d 1016, 139 USPQ 297 (CCPA 1963) 
(Claims were drawn to a hollow fiberglass shaft for archery 
and a process for the production thereof where the shaft dif-
fered from the prior art in the use of a paper tube as the core 
of the shaft as compared with the light wood or hardened 
foamed resin core of the prior art. The Board found the 
claimed invention would have been obvious, reasoning that 
the prior art foam core is the functional and mechanical 
equivalent of the claimed paper core. The court reversed, 
holding that components which are functionally or mechan-
ically equivalent are not necessarily obvious in view of one 
another, and in this case, the use of a light wood or hard-
ened foam resin core does not fairly suggest the use of a 
paper core.); Smith v. Hayashi, 209 USPQ 754 (Bd. of Pat. 
Inter. 1980) (The mere fact that phthalocyanine and sele-
nium function as equivalent photoconductors in the 
claimed environment was not sufficient to establish that 
one would have been obvious over the other. However, 
there was evidence that both phthalocyanine and selenium 
were known photoconductors in the art of electrophotogra-
phy. "This, in our view, presents strong evidence of obvi-
ousness in substituting one for the other in an 
electrophotographic environment as a photoconductor." 
209 USPQ at 759.).

An express suggestion to substitute one equivalent com-
ponent or process for another is not necessary to render 
such substitution obvious. In re Fout, 675 F.2d 297, 213 
USPQ 532 (CCPA 1982).

2144.07	Art Recognized Suitability for 
an Intended Purpose 

The selection of a known material based on its suitability 
for its intended use supported a prima facie obviousness 
determination in Sinclair & Carroll Co. v. Interchemical 
Corp., 325 U.S. 327, 65 USPQ 297 (1945) (Claims to a 
printing ink comprising a solvent having the vapor pressure 
characteristics of butyl carbitol so that the ink would not 
dry at room temperature but would dry quickly upon heat-
ing were held invalid over a reference teaching a printing 
ink made with a different solvent that was nonvolatile at 
room temperature but highly volatile when heated in view 
of an article which taught the desired boiling point and 
vapor pressure characteristics of a solvent for printing inks 
and a catalog teaching the boiling point and vapor pressure 
characteristics of butyl carbitol. "Reading a list and select-
ing a known compound to meet known requirements is no 
more ingenious than selecting the last piece to put in the 
last opening in a jig-saw puzzle." 325 U.S. at 335, 65 
USPQ at 301.).

See also In re Leshin, 227 F.2d 197, 125 USPQ 416 
(CCPA 1960) (selection of a known plastic to make a con-
tainer of a type made of plastics prior to the invention was 
held to be obvious); Ryco, Inc. v. Ag-Bag Corp., 857 F.2d 
1418, 8 USPQ2d 1323 (Fed. Cir. 1988) (Claimed agricul-
tural bagging machine, which differed from a prior art 
machine only in that the brake means were hydraulically 
operated rather than mechanically operated, was held to be 
obvious over the prior art machine in view of references 
which disclosed hydraulic brakes for performing the same 
function, albeit in a different environment.).

2144.08	Obviousness of Species When 
Prior Art Teaches Genus [R-1]

I.	* GUIDELINES FOR THE EXAMINATION OF 
CLAIMS DIRECTED TO SPECIES OF CHEM-
ICAL COMPOSITIONS BASED UPON A SIN-
GLE PRIOR ART REFERENCE

These "Genus-Species Guidelines" are to assist Office 
personnel in the examination of applications which contain 
claims to species or a subgenus of chemical compositions 
for compliance with  35 U.S.C. 103 based upon a single 
prior art reference which discloses a genus encompassing 
the claimed species or subgenus but does not expressly dis-
close the particular claimed species or subgenus. Office 
personnel should attempt to find additional prior art to 
show that the differences between the prior art primary ref-
erence and the claimed invention as a whole would have 
been obvious.  Where such additional prior art is not found, 
Office personnel should follow these guidelines to deter-
mine whether a single reference 35 U.S.C. 103 rejection 
would be appropriate. The guidelines are based on the 
Office's current understanding of the law and are believed 
to be fully consistent with binding precedent of the 
Supreme Court, the Federal Circuit, and the Federal Cir-
cuit's predecessor courts.

The analysis of the guidelines begins at the point during 
examination after a single prior art reference is found dis-
closing a genus encompassing the claimed species or sub-
genus.  Before reaching this point, Office personnel should 
follow *>appropriate antecedent< examination proce-
dures.  Accordingly, Office personnel should first analyze 
the claims as a whole in light of and consistent with the 
written description, considering all claim limitations. When 
evaluating the scope of a claim, every limitation in the 
claim must be considered.  See, e.g., In re Ochiai, 71 F.3d 
1565, 1572, 37 USPQ2d 1127, 1133 (Fed. Cir. 1995).  
However, the claimed invention may not be dissected into 
discrete elements to be analyzed in isolation, but must be 
considered as a whole. See, e.g., W.L. Gore & Assoc., Inc. v. 
Garlock, Inc., 721 F.2d 1540, 1548, 220 USPQ 303, 309 
(Fed. Cir. 1983)**; Jones v. Hardy, 727 F.2d 1524, 1530, 
220 USPQ 1021, 1026 (Fed. Cir. 1983) ("treating the 
advantage as the invention disregards the statutory require-
ment that the invention be viewed `as a whole' ").  Next, 
Office personnel should conduct a thorough search of the 
prior art and identify all relevant references. Both claimed 
and unclaimed aspects of the invention should be searched 
if there is a reasonable expectation that the unclaimed 
aspects may be later claimed. If the most relevant prior art 
consists of a single prior art reference disclosing a genus 
encompassing the claimed species or subgenus, Office per-
sonnel should follow the guidelines set forth herein.

These guidelines do not constitute substantive rulemak-
ing and hence do not have the force and effect of law.  
Rather, they are to assist Office personnel in analyzing 
claimed subject matter for compliance with substantive 
law. Thus, rejections must be based upon the substantive 
law, and it is these rejections which are appealable, not any 
failure by Office personnel to follow these guidelines.

Office personnel are to rely on these guidelines in the 
event of any inconsistent treatment of issues between these 
guidelines and any earlier provided guidance from the 
Office. 

II.	DETERMINE WHETHER THE CLAIMED 
SPECIES OR SUBGENUS WOULD HAVE 
BEEN OBVIOUS TO ONE OF ORDINARY 
SKILL IN THE PERTINENT ART AT THE 
TIME THE INVENTION WAS MADE

The patentability of a claim to a specific compound or 
subgenus embraced by a prior art genus should be analyzed 
no differently than any other claim for purposes of 
35 U.S.C. 103. "The section 103 requirement of unobvious-
ness is no different in chemical cases than with respect to 
other categories of patentable inventions."   In re Papesch, 
315 F.2d 381, 385, 137 USPQ 43, 47 (CCPA 1963).  A 
determination of patentability under  35 U.S.C. 103 should 
be made upon the facts of the particular case in view of the 
totality of the circumstances.  See, e.g., In re Dillon, 919 
F.2d 688, 692-93, 16 USPQ2d 1897, 1901 (Fed. Cir. 1990) 
(in banc)** .  Use of per se rules by Office personnel is 
improper for determining whether claimed subject matter 
would have been obvious under  35 U.S.C. 103.  See, e.g.,   
In re Brouwer, 77 F.3d 422, 425, 37 USPQ2d 1663, 1666 
(Fed. Cir. 1996); In re Ochiai, 71 F.3d 1565, 1572, 
37 USPQ2d 1127, 1133 (Fed. Cir. 1995); In re Baird, 16 
F.3d 380, 382, 29 USPQ2d 1550, 1552 (Fed. Cir. 1994).  
The fact that a claimed species or subgenus is encompassed 
by a prior art genus is not sufficient by itself to establish a 
prima facie case of obviousness. In re Baird, 16 F.3d 380, 
382, 29 USPQ2d 1550, 1552 (Fed. Cir. 1994) ("The fact 
that a claimed compound may be encompassed by a dis-
closed generic formula does not by itself render that com-
pound obvious."); In re Jones, 958 F.2d 347, 350, 21 
USPQ2d 1941, 1943 (Fed. Cir. 1992) (Federal Circuit has 
"decline[d] to extract from Merck [  & Co. v. Biocraft Labo-
ratories Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir. 
1989)] the rule that . . . regardless of how broad, a disclo-
sure of a chemical genus renders obvious any species that 
happens to fall within it.").  See also In re Deuel, 51 F.3d 
1552, 1559, 34 USPQ2d 1210, 1215 (Fed. Cir. 1995). 

A proper obviousness analysis involves a three-step pro-
cess.  First, Office personnel should establish a prima facie 
case of unpatentability considering the factors set out by 
the Supreme Court in Graham v. John Deere. See, e.g., In 
re Bell, 991 F.2d 781, 783, 26 USPQ2d 1529, 1531 (Fed. 
Cir. 1993) ("The PTO bears the burden of establishing a 
case of prima facie obviousness.");   In re Rijckaert, 9 F.3d 
1531, 1532, 28 USPQ2d 1955, 1956 (Fed. Cir. 1993); In re 
Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 
(Fed. Cir. 1992). Graham v. John Deere Co., 383 U.S. 1, 
17-18 (1966), requires that to make out a case of obvious-
ness, one must: 

(A)	determine the scope and contents of the prior art; 

(B)	ascertain the differences between the prior art and 
the claims in issue; 

(C)	determine the level of skill in the pertinent art; and 

(D)	evaluate any evidence of secondary consider-
ations. If a prima facie case is established, the burden shifts 
to applicant to come forward with rebuttal evidence or 
argument to overcome the prima facie case.  

>If a prima facie case is established, the burden shifts to 
applicant to come forward with rebuttal evidence or argu-
ment to overcome the prima facie case.<  See, e.g., Bell, 
991 F.2d at 783-84, 26 USPQ2d at 1531; Rijckaert, 9 F.3d 
at 1532, 28 USPQ2d at 1956; Oetiker, 977 F.2d at 1445, 24 
USPQ2d at 1444  . Finally, Office personnel should evalu-
ate the totality of the facts and all of the evidence to deter-
mine whether they still support a conclusion that the 
claimed invention would have been obvious to one of ordi-
nary skill in the art at the time the invention was made. Id. 

A.	Establishing a Prima Facie Case of Obviousness

To establish a prima facie case of obviousness in a 
genus-species chemical composition situation, as in any 
other  35 U.S.C. 103 case, it is essential that Office person-
nel find some motivation or suggestion to make the claimed 
invention in light of the prior art teachings.  See, e.g., In re 
Brouwer, 77 F.3d 422, 425, 37 USPQ2d 1663, 1666 (Fed. 
Cir. 1996) ("[T]he mere possibility that one of the esters or 
the active methylene group-containing compounds . . . 
could be modified or replaced such that its use would lead 
to the specific sulfoalkylated resin recited in claim 8 does 
not make the process recited in claim 8 obvious `unless the 
prior art suggested the desirability of [such a] modification' 
or replacement.") (quoting In re Gordon, 733 F.2d 900, 
902, 221 USPQ 1125, 1127 (Fed. Cir. 1984)>)<; In re 
Vaeck, 947 F.2d 488, 493, 20 USPQ2d 1438, 1442 (Fed. 
Cir. 1991) ("[A] proper analysis under ? 103 requires, inter 
alia, consideration of . . . whether the prior art would have 
suggested to those of ordinary skill in the art that they 
should make the claimed composition or device, or carry 
out the claimed process.").  In order to find such motivation 
or suggestion there should be a reasonable likelihood that 
the claimed invention would have the properties disclosed 
by the prior art teachings.  The prior art disclosure may be 
express, implicit, or inherent.  Regardless of the type of dis-
closure, the prior art must provide some motivation to one 
of ordinary skill in the art to make the claimed invention in 
order to support a conclusion of obviousness. See, e.g., 
Vaeck, 947 F.2d at 493, 20 USPQ2d at 1442 (A proper 
obviousness analysis requires consideration of "whether 
the prior art would also have revealed that in so making or 
carrying out [the claimed invention], those of ordinary skill 
would have a reasonable expectation of success."); In re 
Dow Chemical Co., 837 F.2d 469, 473, 5 USPQ2d 1529, 
1531 (Fed. Cir. 1988) ("The consistent criterion for deter-
mination of obviousness is whether the prior art would 
have suggested to one of ordinary skill in the art that this 
process should be carried out and would have a reasonable 
likelihood of success, viewed in the light of the prior art."); 
Hodosh v. Block Drug Co., 786 F.2d 1136, 1143 n.5, 229 
USPQ 182, 187 n.5 (Fed. Cir.** 1986).  These disclosed 
findings should be made with a complete understanding of 
the first three "Graham factors."  When evidence of sec-
ondary considerations such as unexpected results is initially 
before the Office, for example in the specification, that evi-
dence should be considered in deciding whether there is a   
prima facie case of obviousness. The determination as to 
whether a prima facie case exists should be made on the 
full record before the Office at the time of the determina-
tion. Thus, Office personnel should: 

(A)	determine the "scope and content of the prior art"; 

(B)	ascertain the "differences between the prior art 
and the claims at issue"; and 

(C)	determine "the level of ordinary skill in the perti-
nent art." 

Graham v. John Deere, 383 U.S. 1, 17, 148 USPQ 459, 467 
(1966). Accord, e.g., In re Paulsen, 30 F.3d 1475, 1482, 31 
USPQ2d 1671, 1676 (Fed. Cir. 1994). 

1.	Determine the Scope and Content of the Prior 
Art 

As an initial matter, Office personnel should determine 
the scope and content of the relevant prior art.  Each refer-
ence must qualify as prior art under  35 U.S.C. 102 (e.g., 
Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1568, 
1 USPQ2d 1593, 1597 (Fed. Cir.** 1987) ("Before answer-
ing Graham's `content' inquiry, it must be known whether a 
patent or publication is in the prior art under 35 U.S.C. 
? 102.")) and should be in the field of applicant's endeavor, 
or be reasonably pertinent to the particular problem with 
which the inventor was concerned.  In re Oetiker, 977 F.2d 
1443, 1447, 24 USPQ2d 1443, 1445 (Fed. Cir. 1992).   
Accord, e.g., In re Clay, 966 F.2d 656, 658-59, 23 USPQ2d 
1058, 1060 (Fed. Cir. 1992).

In the case of a prior art reference disclosing a genus, 
Office personnel should make findings as to: 

(A)	the structure of the disclosed prior art genus and 
that of any expressly described species or subgenus within 
the genus; 

(B)	any physical or chemical properties and utilities 
disclosed for the genus, as well as any suggested limitations 
on the usefulness of the genus, and any problems alleged to 
be addressed by the genus; 

(C)	the predictability of the technology; and 

(D)	the number of species encompassed by the genus 
taking into consideration all of the variables possible. 

2.	Ascertain the Differences Between the >Closest 
Disclosed< Prior Art *>Species or Subgenus of 
Record< and the Claimed Species or Subgenus

Once ** >the structure of the disclosed prior art genus 
and that of any expressly described species or subgenus 
within the genus are< identified, Office personnel should 
compare it to the claimed species or subgenus to determine 
the differences. Through this comparison, the closest dis-
closed species or subgenus in the prior art reference should 
be identified and compared to that claimed. Office person-
nel should make explicit findings on the similarities and 
differences between the closest **>disclosed prior art spe-
cies or subgenus of record< and the claimed species or sub-
genus including findings relating to similarity of structure, 
chemical properties and utilities. In Stratoflex, Inc. v. Aero-
quip Corp., 713 F.2d 1530, 1537, 218 USPQ 871, 877 (Fed. 
Cir. 1983), the Court noted that "the question under 
35 U.S.C. ? 103 is not whether the differences [between the 
claimed invention and the prior art] would have been obvi-
ous" but "whether the claimed invention as a whole would 
have been obvious." (emphasis in original).  

3.	Determine the Level of Skill in the Art

Office personnel should evaluate the prior art from the 
standpoint of the hypothetical person having ordinary skill 
in the art at the time the claimed invention was made.  See, 
Ryko Mfg. Co. v. Nu-Star Inc., 950 F.2d 714, 718, 21 
USPQ2d 1053, 1057 (Fed. Cir. 1991) ("The importance of 
resolving the level of ordinary skill in the art lies in the 
necessity of maintaining objectivity in the obviousness 
inquiry."); Uniroyal Inc. v. Rudkin-Wiley Corp., 837 F.2d 
1044, 1050, 5 USPQ2d 1434, 1438 (Fed. Cir.**1988) (evi-
dence must be viewed from position of ordinary skill, not 
of an expert).  In most cases, the only facts of record per-
taining to the level of skill in the art will be found within 
the prior art reference.  However, any additional evidence 
presented by applicant should be evaluated. 

4.	Determine Whether One of Ordinary Skill in the 
Art Would Have Been Motivated To Select the 
Claimed Species or Subgenus

In light of the findings made relating to the three Gra-
ham factors, Office personnel should determine whether 
one of ordinary skill in the relevant art would have been 
motivated to make the claimed invention as a whole, i.e., to 
select the claimed species or subgenus from the disclosed 
prior art genus.  See, e.g., Ochiai, 71 F.3d at 1569-70, 
37 USPQ2d at 1131; Deuel, 51 F.3d at 1557, 34 USPQ2d at 
1214 ("[A] prima facie case of unpatentability requires that 
the teachings of the prior art suggest the claimed com-
pounds to a person of ordinary skill in the art." (emphasis 
in original)); Jones, 958 F.2d at 351, 21 USPQ2d at 1943-
44 (Fed. Cir. 1992); Dillon, 919 F.2d at 692, 16 USPQ2d at 
1901; In re Lalu, 747 F.2d 703, 705, 223 USPQ 1257, 1258 
(Fed. Cir. 1984) ("The prior art must provide one of ordi-
nary skill in the art the motivation to make the proposed 
molecular modifications needed to arrive at the claimed 
compound.").  See also In re Kemps, 97 F.3d 1427, 1430, 
40 USPQ2d 1309, 1311 (Fed. Cir. 1996) (discussing moti-
vation to combine). To address this key issue, Office per-
sonnel should consider all relevant prior art teachings, 
focusing on the following, where present.  

(a)	Consider the Size of the Genus

Consider the size of the prior art genus, bearing in mind 
that size alone cannot support an obviousness rejection.  
See, e.g., Baird, 16 F.3d at 383, 29 USPQ2d at 1552 
(observing that "it is not the mere number of compounds in 
this limited class which is significant here but, rather, the 
total circumstances involved"). There is no absolute corre-
lation between the size of the prior art genus and a conclu-
sion of obviousness.  Id.  Thus, the mere fact that a prior art 
genus contains a small number of members does not create 
a per se rule of obviousness.  Some motivation to select the 
claimed species or subgenus must be taught by the prior art. 
See, e.g., Deuel, 51 F.3d at 1558-59, 34 USPQ2d at 1215 
("No particular one of these DNAs can be obvious unless 
there is something in the prior art to lead to the particular 
DNA and indicate that it should be prepared.");   Baird, 16 
F.3d at 382-83, 29 USPQ2d at 1552; Bell, 991 F.2d at 784, 
26 USPQ2d at 1531 ("Absent anything in the cited prior art 
suggesting which of the 1036 possible sequences suggested 
by Rinderknecht corresponds to the IGF gene, the PTO has 
not met its burden of establishing that the prior art would 
have suggested the claimed sequences.").  However, a 
genus may be so small that >, when considered in light of 
the totality of the circumstances,< it would anticipate the 
claimed species or subgenus.  For example, it has been held 
that a prior art genus containing only 20 compounds >and a 
limited number of variations in the generic chemical for-
mula< inherently anticipated a claimed species within the 
genus because "one skilled in [the] art would ... envisage 
each member" of the genus.  In re Petering, 301 F.2d 676, 
681, 133 USPQ 275, 280 (CCPA 1962) (emphasis in origi-
nal).  >More specifically, the court in Petering stated:

  A simple calculation will show that, excluding isomerism within 
certain of the R groups, the limited class we find in Karrer con-
tains only 20 compounds. However, we wish to point out that it is 
not the mere number of compounds in this limited class which is 
significant here but, rather, the total circumstances involved, 
including such factors as the limited number of variations for R, 
only two alternatives for Y and Z, no alternatives for the other 
ring positions, and a large unchanging parent structural nucleus. 
With these circumstances in mind, it is our opinion that Karrer 
has described to those with ordinary skill in this art each of the 
various permutations here involved as fully as if he had drawn 
each structural formula or had written each name.

Id. (emphasis in original).<  Accord In re Schaumann, 572 
F.2d 312, 316, 197 USPQ 5, 9 (CCPA 1978) (prior art 
genus encompassing claimed species which disclosed pref-
erence for lower alkyl secondary amines and properties 
possessed by the claimed compound constituted description 
of claimed compound for purposes of  35 U.S.C. 102(b)). 
C.f., In re Ruschig, 343 F.2d 965, 974, 145 USPQ 274, 282 
(CCPA 1965) (Rejection of claimed compound in light of 
prior art genus based on Petering is not appropriate where 
the prior art does not disclose a small recognizable class of 
compounds with common properties.).

(b)	Consider the Express Teachings

If the prior art reference expressly teaches a particular 
reason to select the claimed species or subgenus, Office 
personnel should point out the express disclosure which 
would have motivated one of ordinary skill in the art to 
select the claimed invention.  An express teaching may be 
based on a statement in the prior art reference such as an art 
recognized equivalence.  For example, see Merck & Co. v. 
Biocraft Labs., 874 F.2d 804, 807, 10 USPQ2d 1843, 1846 
(Fed. Cir.** 1989) (holding claims directed to diuretic 
compositions comprising a specific mixture of amiloride 
and hydrochlorothiazide were obvious over a prior art ref-
erence expressly teaching that amiloride was a pyrazi-
noylguanidine which could be coadministered with 
potassium excreting diuretic agents, including hydrochlo-
rothiazide which was a named example, to produce a 
diuretic with desirable sodium and potassium eliminating 
properties). See also, In re Kemps, 97 F.3d 1427, 1430, 40 
USPQ2d 1309, 1312 (Fed. Cir. 1996) (holding there is suf-
ficient motivation to combine teachings of prior art to 
achieve claimed invention where one reference specifically 
refers to the other). 

(c)	Consider the Teachings of Structural Similarity

Consider any teachings of a "typical," "preferred," or 
"optimum" species or subgenus within the disclosed genus.  
If such a species or subgenus is structurally similar to that 
claimed, its disclosure may motivate one of ordinary skill 
in the art to choose the claimed species or subgenus from 
the genus, based on the reasonable expectation that struc-
turally similar species usually have similar properties. See, 
e.g., Dillon, 919 F.2d at 693, 696, 16 USPQ2d at 1901, 
1904.  See also Deuel, 51 F.3d at 1558, 34 USPQ2d at 1214 
("Structural relationships may provide the requisite motiva-
tion or suggestion to modify known compounds to obtain 
new compounds. For example, a prior art compound may 
suggest its homologs because homologs often have similar 
properties and therefore chemists of ordinary skill would 
ordinarily contemplate making them to try to obtain com-
pounds with improved properties."). The utility of such 
properties will normally provide some motivation to make 
the claimed species or subgenus.  Id.

In making an obviousness determination, Office person-
nel should consider the number of variables which must be 
selected or modified, and the nature and significance of the 
differences between the prior art and the claimed invention. 
See, e.g., In re Jones, 958 F.2d 347, 350, 21 USPQ2d 1941, 
1943 (Fed. Cir. 1992) (reversing obviousness rejection of 
novel dicamba salt with acyclic structure over broad prior 
art genus encompassing claimed salt, where disclosed 
examples of genus were dissimilar in structure, lacking an 
ether linkage or being cyclic); In re Susi, 440 F.2d 442, 445, 
169 USPQ 423, 425 (CCPA 1971) (the difference from the 
particularly preferred subgenus of the prior art was a 
hydroxyl group, a difference conceded by applicant "to be 
of little importance").  In the area of biotechnology, an 
exemplified species may differ from a claimed species by 
a conservative substitution ("the replacement in a protein 
of one amino acid by another, chemically similar, amino 
acid . . . [which] is generally expected to lead to either no 
change or only a small change in the properties of the pro-
tein." Dictionary of Biochemistry and Molecular Biology 
97  (John Wiley & Sons, 2d ed. 1989)).  The effect of a con-
servative substitution on protein function depends on the 
nature of the substitution and its location in the chain. 
Although at some locations a conservative substitution may 
be benign, in some proteins only one amino acid is allowed 
at a given position.  For example, the gain or loss of even 
one methyl group can destabilize the structure if close 
packing is required in the interior of domains. James Dar-
nell et al., Molecular Cell Biology  51  (2d ed. 1990).  

The closer the physical and chemical similarities 
between the claimed species or subgenus and any exem-
plary species or subgenus disclosed in the prior art, the 
greater the expectation that the claimed subject matter will 
function in an equivalent manner to the genus. See, e.g., 
Dillon, 919 F.2d at 696, 16 USPQ2d at 1904 (and cases 
cited therein). Cf. Baird, 16 F.3d at 382-83, 29 USPQ2d at 
1552 (disclosure of dissimilar species can provide teaching 
away). 

Similarly, consider any teaching or suggestion in the ref-
erence of a preferred species or subgenus that is signifi-
cantly different in structure from the claimed species or 
subgenus.  Such a teaching may weigh against selecting the 
claimed species or subgenus and thus against a determina-
tion of obviousness.  Baird, 16 F.3d at 382-83, 29 USPQ2d 
at 1552 (reversing obviousness rejection of species in view 
of large size of genus and disclosed "optimum" species 
which differed greatly from and were more complex than 
the claimed species); Jones, 958 F.2d at 350, 21 USPQ2d at 
1943 (reversing obviousness rejection of novel dicamba 
salt with acyclic structure over broad prior art genus 
encompassing claimed salt, where disclosed examples of 
genus were dissimilar in structure, lacking an ether linkage 
or being cyclic).  For example, teachings of preferred spe-
cies of a complex nature within a disclosed genus may 
motivate an artisan of ordinary skill to make similar com-
plex species and thus teach away from making simple spe-
cies within the genus. Baird, 16 F.3d at 382, 29 USPQ2d at 
1552.  See also Jones, 958 F.2d at 350, 21 USPQ2d at 1943 
(disclosed salts of genus held not sufficiently similar in 
structure to render claimed species prima facie obvious).  

Concepts used to analyze the structural similarity of 
chemical compounds in other types of chemical cases are 
equally useful in analyzing genus-species cases. For exam-
ple, a claimed tetra-orthoester fuel composition was held to 
be obvious in light of a prior art tri-orthoester fuel composi-
tion based on their structural and chemical similarity and 
similar use as fuel additives. Dillon, 919 F.2d at 692-93, 16 
USPQ2d at 1900-02. Likewise, claims to amitriptyline used 
as an antidepressant were held obvious in light of the struc-
tural similarity to imipramine, a known antidepressant prior 
art compound, where both compounds were tricyclic 
dibenzo compounds and differed structurally only in the 
replacement of the unsaturated carbon atom in the center 
ring of amitriptyline with a nitrogen atom in imipramine. In 
re Merck & Co., 800 F.2d 1091, 1096-97, 231 USPQ 375, 
378-79 (Fed. Cir. 1986).  **  Other structural similarities 
have been found to support a prima facie case of obvious-
ness. See, e.g., In re May, 574 F.2d 1082, 1093-95, 197 
USPQ 601, 610-11 (CCPA 1978) (stereoisomers); In re 
Wilder, 563 F.2d 457, 460, 195 USPQ 426, 429 (CCPA 
1977) (adjacent homologs and structural isomers); In re 
Hoch, 428 F.2d 1341, 1344, 166 USPQ 406, 409 (CCPA 
1970) (acid and ethyl ester); In re Druey, 319 F.2d 237, 
240, 138 USPQ 39, 41 (CCPA 1963) (omission of methyl 
group from pyrazole ring). Generally, some teaching of a 
structural similarity will be necessary to suggest selection 
of the claimed species or subgenus. Id.  

(d)	Consider the Teachings of Similar Properties or 
Uses

Consider the properties and utilities of the structurally 
similar prior art species or subgenus.  It is the properties 
and utilities that provide real world motivation for a person 
of ordinary skill to make species structurally similar to 
those in the prior art. Dillon, 919 F.2d at 697, 16 USPQ2d 
at 1905;  In re Stemniski, 444 F.2d 581, 586, 170 USPQ 
343, 348 (CCPA 1971). Conversely, lack of any known 
useful properties weighs against a finding of motivation to 
make or select a species or subgenus.  In re Albrecht, 514 
F.2d 1389, 1392, 1395-96, 185 USPQ 585, 587, 590 (CCPA 
1975) (The prior art compound so irritated the skin that it 
could not be regarded as useful for the disclosed anesthetic 
purpose, and therefore a person skilled in the art would not 
have been motivated to make related compounds.); Stemni-
ski, 444 F.2d at 586, 170 USPQ at 348 (close structural sim-
ilarity alone is not sufficient to create a prima facie case of 
obviousness when the reference compounds lack utility, 
and thus there is no motivation to make related com-
pounds.).  However, the prior art need not disclose a newly 
discovered property in order for there to be a prima facie 
case of obviousness. Dillon, 919 F.2d at 697, 16 USPQ2d at 
1904-05 (and cases cited therein). If the claimed invention 
and the structurally similar prior art species share *>any< 
useful property, that will generally be sufficient to motivate 
an artisan of ordinary skill to make the claimed species, 
e.g., id.  For example, based on a finding that a tri-orthoe-
ster and a tetra-orthoester behave similarly in certain chem-
ical reactions, it has been held that one of ordinary skill in 
the relevant art would have been motivated to select either 
structure.  919 F.2d at 692, 16 USPQ2d at 1900-01. In fact, 
similar properties may normally be presumed when com-
pounds are very close in structure. Dillon, 919 F.2d at 693, 
696, 16 USPQ2d at 1901, 1904.  See also In re Grabiak, 
769 F.2d 729, 731, 226 USPQ 870, 871 (Fed. Cir. 1985) 
("When chemical compounds have `very close' structural 
similarities and similar utilities, without more a prima facie 
case may be made.").  Thus, evidence of similar properties 
>or evidence of any useful properties disclosed in the prior 
art that would be expected to be shared by the claimed 
invention< weighs in favor of a conclusion that the claimed 
invention would have been obvious.  Dillon, 919 F.2d at 
697-98, 16 USPQ2d at 1905;  In re Wilder, 563 F.2d 457, 
461, 195 USPQ 426, 430 (CCPA 1977); In re Linter, 458 
F.2d 1013, 1016, 173 USPQ 560, 562 (CCPA 1972). 

(e)	Consider the Predictability of the Technology

Consider the predictability of the technology. See, e.g., 
Dillon, 919 F.2d at 692-97, 16 USPQ2d at 1901-05; In re 
Grabiak, 769 F.2d 729, 732-33, 226 USPQ 870, 872 (Fed. 
Cir. 1985).  If the technology is unpredictable, it is less 
likely that structurally similar species will render a claimed 
species obvious because it may not be reasonable to infer 
that they would share similar properties.  See, e.g., In re 
May, 574 F.2d 1082, 1094, 197 USPQ 601, 611 (CCPA 
1978) (prima facie obviousness of claimed analgesic com-
pound based on structurally similar prior art isomer was 
rebutted with evidence demonstrating that analgesia and 
addiction properties could not be reliably predicted on the 
basis of chemical structure); In re Schechter, 205 F.2d 185, 
191, 98 USPQ 144, 150 (CCPA 1953) (unpredictability in 
the insecticide field, with homologs, isomers and analogs 
of known effective insecticides having proven ineffective 
as insecticides, was considered as a factor weighing against 
a conclusion of obviousness of the claimed compounds). 
However, obviousness does not require absolute predict-
ability, only a reasonable expectation of success, i.e., a rea-
sonable expectation of obtaining similar properties. See, 
e.g., In re O'Farrell, 853 F.2d 894, 903, 7 USPQ2d 1673, 
1681 (Fed. Cir. 1988). 

(f)	Consider Any Other Teaching To Support the 
Selection of the Species or Subgenus

The categories of relevant teachings enumerated above 
are those most frequently encountered in a genus-species 
case, but they are not exclusive.  Office personnel should 
consider the totality of the evidence in each case.  In 
unusual cases, there may be other relevant teachings suffi-
cient to support the selection of the species or subgenus 
and, therefore, a conclusion of obviousness. 

5.	Make Express Fact-Findings and Determine 
Whether They Support a Prima Facie Case of 
Obviousness

Based on the evidence as a whole (In re Bell, 991 F.2d 
781,784, 26 USPQ2d 1529, 1531 (Fed. Cir. 1993); In re 
Kulling, 897 F.2d 1147, 1149, 14 USPQ2d 1056, 1057 
(Fed. Cir. 1990)), Office personnel should make express 
fact-findings relating to the Graham factors, focusing pri-
marily on the prior art teachings discussed above.  The fact-
findings should specifically articulate what teachings or 
suggestions in the prior art would have motivated one of 
ordinary skill in the art to select the claimed species or sub-
genus. Kulling, 897 F.2d at 1149, 14 USPQ2d at 1058; Pan-
duit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1579 n.42, 
1 USQP2d 1593, 1606 n.42 (Fed. Cir.** 1987).  Thereafter, 
it should be determined whether these findings, considered 
as a whole, support a prima facie case that the claimed 
invention would have been obvious to one of ordinary skill 
in the relevant art at the time the invention was made.  

B.	Determining Whether Rebuttal Evidence Is 
Sufficient To Overcome the Prima Facie Case of 
Obviousness

If a prima facie case of obviousness is established, the 
burden shifts to the applicant to come forward with argu-
ments and/or evidence to rebut the prima facie case. See, 
e.g., Dillon, 919 F.2d at 692, 16 USPQ2d at 1901.  Rebuttal 
evidence and arguments can be presented in the specifica-
tion, In re Soni, 54 F.3d 746, 750, 34 USPQ2d 1684, 1687 
(Fed. Cir. 1995), by counsel, In re Chu, 66 F.3d 292, 299, 
36 USPQ2d 1089, 1094-95 (Fed. Cir. 1995), or by way of 
an affidavit or declaration under  37 CFR 1.132, e.g., Soni, 
54 F.3d at 750, 34 USPQ2d at 1687; In re Piasecki, 745 
F.2d 1468, 1474, 223 USPQ 785, 789-90 (Fed. Cir. 1984). 
However, arguments of counsel cannot take the place of 
factually supported objective evidence. See, e.g., In re 
Huang, 100 F.3d 135, 139-40, 40 USPQ2d 1685, 1689 
(Fed. Cir. 1996); In re De Blauwe, 736 F.2d 699, 705, 222 
USPQ 191, 196 (Fed. Cir. 1984).

Office personnel should consider all rebuttal arguments 
and evidence presented by applicants. See, e.g., In re Soni, 
54 F.3d 746, 750, 34 USPQ2d 1684, 1687 (Fed. Cir. 1995) 
(error not to consider evidence presented in the specifica-
tion). C.f., In re Alton, 76 F.3d 1168, 37 USPQ2d 1578 
(Fed. Cir. 1996) (error not to consider factual evidence sub-
mitted to counter a 35 U.S.C. 112 rejection); In re Beattie, 
974 F.2d 1309, 1313, 24 USPQ2d 1040, 1042-43 (Fed. Cir. 
1992) (Office personnel should consider declarations from 
those skilled in the art praising the claimed invention and 
opining that the art teaches away from the invention.);   
Piasecki, 745 F.2d at 1472, 223 USPQ at 788 ("[Rebuttal 
evidence] may relate to any of the Graham factors includ-
ing the so-called secondary considerations."). Rebuttal evi-
dence may include evidence of "secondary considerations," 
such as "commercial success, long felt but unsolved needs, 
[and] failure of others." Graham v. John Deere Co., 383 
U.S. at 17, 148 USPQ at 467. See also, e.g., In re Piasecki, 
745 F.2d 1468, 1473, 223 USPQ 785, 788 (Fed. Cir. 1984) 
(commercial success). Rebuttal evidence may also include 
evidence that the claimed invention yields unexpectedly 
improved properties or properties not present in the prior 
art.  Rebuttal evidence may consist of a showing that the 
claimed compound possesses unexpected properties. Dil-
lon, 919 F.2d at 692-93, 16 USPQ2d at 1901.  A showing of 
unexpected results must be based on evidence, not argu-
ment or speculation. In re Mayne, 104 F.3d 1339, 1343-44, 
41 USPQ2d 1451, 1455>-56< (Fed. Cir. 1997) (conclusory 
statements that claimed compound possesses unusually low 
immune response or unexpected biological activity that is 
unsupported by comparative data held insufficient to over-
come prima facie case of obviousness).  Rebuttal evidence 
may include evidence that the claimed invention was cop-
ied by others. See, e.g., In re GPAC, 57 F.3d 1573, 1580, 
35 USPQ2d 1116, 1121 (Fed. Cir. 1995); Hybritech Inc. v. 
Monoclonal Antibodies, 802 F.2d 1367, 1380, 231 USPQ 
81, 90 (Fed. Cir. 1986)**. It may also include evidence of 
the state of the art, the level of skill in the art, and the 
beliefs of those skilled in the art. See, e.g., In re Oelrich, 
579 F.2d 86, 91-92, 198 USPQ 210, 214 (CCPA 1978) 
(Expert opinions regarding the level of skill in the art were 
probative of the Nonobviousness of the claimed inven-
tion.); Piasecki, 745 F.2d at 1471, 1473-74, 223 USPQ at 
790 (Evidence of nontechnological nature is pertinent to 
the conclusion of obviousness.  The declarations of those 
skilled in the art regarding the need for the invention and its 
reception by the art were improperly discounted by the 
Board.); Beattie, 974 F.2d at 1313, 24 USPQ2d at 1042-43 
(Seven declarations provided by music teachers opining 
that the art teaches away from the claimed invention must 
be considered, but were not probative because they did not 
contain facts and did not deal with the specific prior art that 
was the subject of the rejection.).  >For example, rebuttal 
evidence may include a showing that the prior art fails to 
disclose or render obvious a method for making the com-
pound, which would preclude a conclusion of obviousness 
of the compound. A conclusion of obviousness requires 
that the reference(s) relied upon be enabling in that it put 
the public in possession of the claimed invention. The court 
in In re Hoeksema, 399 F.2d 269, 274, 158 USPQ 596, 601 
(CCPA 1968), stated:  

  Thus, upon careful reconsideration it is our view that if the 
prior art of record fails to disclose or render obvious a method for 
making a claimed compound, at the time the invention was made, 
it may not be legally concluded that the compound itself is in the 
possession of the public. [footnote omitted.] In this context, we 
say that the absence of a known or obvious process for making 
the claimed compounds overcomes a presumption that the com-
pounds are obvious, based on close relationships between their 
structures and those of prior art compounds.

The Hoeksema court further noted that once a prima 
facie case of obviousness is made by the PTO through cita-
tion of references, the burden is on the applicant to produce 
contrary evidence establishing that the reference being 
relied on would not enable a skilled artisan to produce the 
different compounds claimed. Id. at 274-75, 158 USPQ at 
601. See also Ashland Oil, Inc. v. Delta Resins & Refracto-
ries, Inc., 776 F.2d 281, 295, 297, 227 USPQ 657, 666, 667 
(Fed. Cir. 1985) (citing Hoeksema for the proposition 
above); In re Grose, 592 F.2d 1161, 1168, 201 USPQ 57, 
63-64 (CCPA 1979) ("One of the assumptions underlying a 
prima facie obviousness rejection based upon a structural 
relationship between compounds, such as adjacent 
homologs, is that a method disclosed for producing one 
would provide those skilled in the art with a method for 
producing the other . . . Failure of the prior art to disclose or 
render obvious a method for making any composition of 
matter, whether a compound or a mixture of compounds 
like a zeolite, precludes a conclusion that the composition 
would have been obvious.").<

Consideration of rebuttal evidence and arguments 
requires Office personnel to weigh the proffered evidence 
and arguments. Office personnel should avoid giving evi-
dence no weight, except in rare circumstances. Id. See also 
In re Alton, 76 F.3d 1168, 1174-75, 37 USPQ2d 1578, 
1582-83 (Fed. Cir. 1996).  However, to be entitled to sub-
stantial weight, the applicant should establish a nexus 
between the rebuttal evidence and the claimed invention,   
i.e., objective evidence of nonobviousness must be attribut-
able to the claimed invention.  The Federal Circuit has 
acknowledged that applicant bears the burden of establish-
ing nexus, stating:

In the ex parte process of examining a patent application, how-
ever, the PTO lacks the means or resources to gather evidence 
which supports or refutes the applicant's assertion that the sales 
constitute commercial success. C.f. Ex parte Remark, 15 
USPQ2d 1498, 1503 ([BPAI] 1990) (evidentiary routine of shift-
ing burdens in civil proceedings inappropriate in ex parte prose-
cution proceedings because examiner has no available means for 
adducing evidence).  Consequently, the PTO must rely upon the 
applicant to provide hard evidence of commercial success.

In re Huang, 100 F.3d 135, 139-40, 40 USPQ2d 1685, 1689 
(Fed. Cir. 1996).  See also GPAC, 57 F.3d at 1580, 35 
USPQ2d at 1121; In re Paulsen, 30 F.3d 1475, 1482, 31 
USPQ2d 1671, 1676 (Fed. Cir. 1994) (Evidence of com-
mercial success of articles not covered by the claims sub-
ject to the  35 U.S.C. 103 rejection was not probative of 
nonobviousness.). Additionally, the evidence must be rea-
sonably commensurate in scope with the claimed invention. 
See *, e.g.,  In re Kulling, 897 F.2d 1147, 1149, 14 USPQ2d 
1056, 1058 (Fed. Cir. 1990); In re Grasselli, 713 F.2d 731, 
743, 218 USPQ 769, 777 (Fed. Cir. 1983). In re Soni, 54 
F.3d 746, 34 USPQ2d 1684 (Fed. Cir. 1995) does not 
change this analysis. In   Soni, the Court declined to con-
sider the Office's argument that the evidence of nonobvi-
ousness was not commensurate in scope with the claim 
because it had not been raised by the Examiner (54 F.3d at 
751, 34 USPQ2d at 1688).  

When considering whether proffered evidence is com-
mensurate in scope with the claimed invention, Office per-
sonnel should not require the applicant to show 
unexpected results over the entire range of properties 
possessed by a chemical compound or composition.  See, 
e.g., In re Chupp, 816 F.2d 643, 646, 2 USPQ2d 1437, 1439 
(Fed. Cir. 1987). Evidence that the compound or composi-
tion possesses superior and unexpected properties in one of 
a spectrum of common properties can be sufficient to rebut 
a prima facie case of obviousness. Id.  

For example, a showing of unexpected results for a sin-
gle member of a claimed subgenus, or a narrow portion of a 
claimed range would be sufficient to rebut a prima facie 
case of obviousness if a skilled artisan "could ascertain a 
trend in the exemplified data that would allow him to rea-
sonably extend the probative value thereof." In re Clemens, 
622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980) 
(Evidence of the unobviousness of a broad range can be 
proven by a narrower range when one skilled in the art 
could ascertain a trend that would allow him to reasonably 
extend the probative value thereof.).  But see, Grasselli, 
713 F.2d at 743, 218 USPQ at 778 (evidence of superior 
properties for sodium containing composition insufficient 
to establish the non-obviousness of broad claims for a cata-
lyst with "an alkali metal" where it was well known in the 
catalyst art that different alkali metals were not inter-
changeable and applicant had shown unexpected results 
only for sodium containing materials); In re Greenfield, 
571 F.2d 1185, 1189, 197 USPQ 227, 230 (CCPA 1978) 
(evidence of superior properties in one species insufficient 
to establish the nonobviousness of a subgenus containing 
hundreds of compounds); In re Lindner, 457 F.2d 506, 508, 
173 USPQ 356, 358 (CCPA 1972) (one test not sufficient 
where there was no adequate basis for concluding the other 
claimed compounds would behave the same way). How-
ever, an exemplary showing may be sufficient to establish a 
reasonable correlation between the showing and the entire 
scope of the claim, when viewed by a skilled artisan. See,  
e.g., Chupp, 816 F.2d at 646, 2 USPQ2d at 1439; Clemens, 
622 F.2d at 1036, 206 USPQ at 296.  On the other hand, 
evidence of an unexpected property may not be sufficient 
regardless of the scope of the showing.  * >Usually, a 
showing of unexpected results is sufficient to overcome a 
prima facie case of obviousness.  See, e.g., In re Albrecht, 
514 F.2d 1389, 1396, 185 USPQ 585, 590 (CCPA 1975). 
However, where< the claims are not limited to a particular 
use, and where the prior art provides other motivation to 
select a particular species or subgenus, a showing of a new 
use may not be sufficient to confer patentability.  See Dil-
lon, 919 F.2d at 692, 16 USPQ2d at 1900-01. Accordingly, 
each case should be evaluated individually based on the 
totality of the circumstances. 

Office personnel should not evaluate rebuttal evidence 
for its "knockdown" value against the prima facie case, 
Piasecki, 745 F.2d at 1473, 223 USPQ at 788, or summarily 
dismiss it as not compelling or insufficient. If the evidence 
is deemed insufficient to rebut the prima facie case of obvi-
ousness, Office personnel should specifically set forth the 
facts and reasoning that justify this conclusion.

III.	RECONSIDER ALL EVIDENCE AND 
CLEARLY COMMUNICATE FINDINGS AND 
CONCLUSIONS

A determination under  35 U.S.C. 103 should rest on all 
the evidence and should not be influenced by any earlier 
conclusion. See, e.g., Piasecki, 745 F.2d at 1472-73, 223 
USPQ at 788; In re Eli Lilly & Co., 902 F.2d 943, 945, 14 
USPQ2d 1741, 1743 (Fed. Cir. 1990).  Thus, once the 
applicant has presented rebuttal evidence, Office personnel 
should reconsider any initial obviousness determination in 
view of the entire record. See, e.g., Piasecki, 745 F.2d at 
1472, 223 USPQ at 788; Eli Lilly, 902 F.2d at 945, 14 
USPQ2d at 1743.  All the proposed rejections and their 
bases should be reviewed to confirm their correctness.  
Only then should any rejection be imposed in an Office 
action. The Office action should clearly communicate the 
Office's findings and conclusions, articulating how the con-
clusions are supported by the findings.  

Where applicable, the findings should clearly articulate 
which portions of the reference support any rejection. 
Explicit findings on motivation or suggestion to select the 
claimed invention should also be articulated in order to 
support a 35 U.S.C. 103 ground of rejection.   Dillon, 919 
F.2d at 693, 16 USPQ2d at 1901; In re Mills, 916 F.2d 680, 
683, 16 USPQ2d 1430, 1433 (Fed. Cir. 1990). Conclusory 
statements of similarity or motivation, without any articu-
lated rationale or evidentiary support, do not constitute suf-
ficient factual findings.**

2144.09	Close Structural Similarity 
Between Chemical Compounds 
(Homologs, Analogues, Isomers)

REJECTION BASED ON CLOSE STRUCTURAL 
SIMILARITY IS FOUNDED ON THE EXPECTA-
TION THAT COMPOUNDS SIMILAR IN STRUC-
TURE WILL HAVE SIMILAR PROPERTIES 

A prima facie case of obviousness may be made when 
chemical compounds have very close structural similarities 
and similar utilities. "An obviousness rejection based on 
similarity in chemical structure and function entails the 
motivation of one skilled in the art to make a claimed com-
pound, in the expectation that compounds similar in struc-
ture will have similar properties." In re Payne, 606 F.2d 
303, 313, 203 USPQ 245, 254 (CCPA 1979). See In re 
Papesch, 315 F.2d 381, 137 USPQ 43 (CCPA 1963) (dis-
cussed in more detail below) and In re Dillon, 919 F.2d 
688, 16 USPQ2d 1897 (Fed. Cir. 1991) (discussed below 
and in  MPEP ? 2144) for an extensive review of the case 
law pertaining to obviousness based on close structural 
similarity of chemical compounds. See also MPEP 
? 2144.08, paragraph II.A.4.(c).

HOMOLOGY AND ISOMERISM ARE FACTS 
WHICH MUST BE CONSIDERED WITH ALL 
OTHER RELEVANT FACTS IN DETERMINING 
OBVIOUSNESS 

Compounds which are position isomers (compounds 
having the same radicals in physically different positions 
on the same nucleus) or homologs (compounds differing 
regularly by the successive addition of the same chemical 
group, e.g., by -CH2- groups) are generally of sufficiently 
close structural similarity that there is a presumed expecta-
tion that such compounds possess similar properties. In re 
Wilder, 563 F.2d 457, 195 USPQ 426 (CCPA 1977). See 
also In re May, 574 F.2d 1082, 197 USPQ 601 (CCPA 
1978) (stereoisomers prima facie obvious).

Isomers having the same empirical formula but different 
structures are not necessarily considered equivalent by 
chemists skilled in the art and therefore are not necessarily 
suggestive of each other. Ex parte Mowry, 91 USPQ 219 
(Bd. App. 1950) (claimed cyclohexylstyrene not prima 
facie obvious over prior art isohexylstyrene). Similarly, 
homologs which are far removed from  adjacent homologs 
may not be expected to have similar properties. In re Mills, 
281 F.2d 218, 126 USPQ 513 (CCPA 1960) (prior art dis-
closure of C8 to C12 alkyl sulfates was not sufficient to ren-
der prima facie obvious claimed C1 alkyl sulfate).

Homology and isomerism involve close structural simi-
larity which must be considered with all other relevant facts 
in determining the issue of obviousness. In re Mills, 281 
F.2d 218, 126 USPQ 513 (CCPA 1960); In re Wiechert, 370 
F.2d 927, 152 USPQ 247 (CCPA 1967). Homology should 
not be automatically equated with   prima facie obvious-
ness because the claimed invention and the prior art must 
each be viewed "as a whole." In re Langer, 465 F.2d 896, 
175 USPQ 169 (CCPA 1972) (Claims to a polymerization 
process using a sterically hindered amine were held unob-
vious over a similar prior art process because the prior art 
disclosed a large number of unhindered amines and only 
one sterically hindered amine (which differed from a 
claimed amine by 3 carbon atoms), and therefore the refer-
ence as a whole did not apprise the ordinary artisan of the 
significance of hindered amines as a class.). 

PRESENCE OF A TRUE HOMOLOGOUS OR ISO-
MERIC RELATIONSHIP IS NOT CONTROLLING

Prior art structures do not have to be true homologs or 
isomers to render structurally similar compounds prima 
facie obvious. In re Payne, 606 F.2d 303, 203 USPQ 245 
(CCPA 1979) (Claimed and prior art compounds were both 
directed to heterocyclic carbamoyloximino compounds 
having pesticidal activity. The only structural difference 
between the claimed and prior art compounds was that the 
ring structures of the claimed compounds had two carbon 
atoms between two sulfur atoms whereas the prior art ring 
structures had either one or three carbon atoms between 
two sulfur atoms. The court held that although the prior art 
compounds were not true homologs or isomers of the 
claimed compounds, the similarity between the chemical 
structures and properties is sufficiently close that one of 
ordinary skill in the art would have been motivated to make 
the claimed compounds in searching for new pesticides.).  

See also In re Mayne, 104 F.3d 1339, 41 USPQ2d 1451 
(Fed. Cir. 1997) (claimed protein was held to be obvious in 
light of structural similarities to the prior art, including 
known structural similarity of Ile and Len); In re Merck & 
Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) 
(claimed and prior art compounds used in a method of 
treating depression would have been expected to have simi-
lar activity because the structural difference between the 
compounds involved a known bioisosteric replacement) 
(see MPEP ? 2144.08, paragraph II.A.4(c) for a more 
detailed discussion of the facts in the Mayne and Merck 
cases); In re Dillon, 919 F.2d 688, 16 USPQ2d 1897 (Fed. 
Cir. 1991) (The tri-orthoester fuel compositions of the prior 
art and the claimed tetra-orthoester fuel compositions 
would have been expected to have similar properties based 
on close structural and chemical similarity between the 
orthoesters and the fact that both the prior art and applicant 
used the orthoesters as fuel additives.) (See  MPEP ? 2144 
for a more detailed discussion of the facts in the Dillon 
case.).

Compare In re Grabiak, 769 F.2d 729, 226 USPQ 871 
(Fed. Cir. 1985) (substitution of a thioester group for an 
ester group in an herbicidal safener compound was not sug-
gested by the prior art); In re Bell, 991 F.2d 781, 26 
USPQ2d 1529 (Fed. Cir. 1993) (The established relation-
ship between a nucleic acid and the protein it en codes in 
the genetic code does not render a gene prima facie obvious 
over its corresponding protein in the same way that closely 
related structures in chemistry may create a prima facie 
case because there are a vast number of nucleotide 
sequences that might encode for a specific protein as a 
result of degeneracy in the genetic code (i.e., the fact that 
most amino acids are specified by more than one nucleotide 
sequence or codon).); In re Deuel, 51 F.3d 1552, 1558-59, 
34 USPQ2d 1210, 1215 (Fed. Cir. 1995) ("A prior art dis-
closure of the amino acid sequence of a protein does not 
necessarily render particular DNA molecules encoding the 
protein obvious because the redundancy of the genetic code 
permits one to hypothesize an enormous number of DNA 
sequences coding for the protein." The existence of a gen-
eral method of gene cloning in the prior art is not sufficient, 
without more, to render obvious a particular cDNA mole-
cule.). 

PRESENCE OR ABSENCE OF PRIOR ART  SUG-
GESTION OF METHOD OF MAKING A CLAIMED 
COMPOUND MAY BE RELEVANT IN DETERMIN-
ING PRIMA FACIE OBVIOUSNESS

"[T]he presence-or absence-of a suitably operative, 
obvious process for making a composition of matter may 
have an ultimate bearing on whether that composition is 
obvious-or nonobvious-under  35 U.S.C. 103."  In re 
Maloney, 411 F.2d 1321, 1323, 162 USPQ 98, 100 (CCPA 
1969).

"[I]f the prior art of record fails to disclose or render 
obvious a method for making a claimed compound, at the 
time the invention was made, it may not be legally con-
cluded that the compound itself is in the possession of the 
public. In this context, we say that the absence of a known 
or obvious process for making the claimed compounds 
overcomes a presumption that the compounds are obvious, 
based on the close relationships between their structures 
and those of prior art compounds." In re Hoeksema, 399 
F.2d 269, 274-75, 158 USPQ 597, 601 (CCPA 1968). 

See In re Payne, 606 F.2d 303, 203 USPQ 245 (CCPA 
1979) for a general discussion of circumstances under 
which the prior art suggests methods for making novel 
compounds which are of close structural similarity to com-
pounds known in the prior art.  In the biotechnology arts, 
the existence of a general method of gene cloning in the 
prior art is not sufficient, without more, to render obvious a 
particular cDNA molecule. In re Deuel, 51 F.3d 1552, 
1558, 34 USPQ2d 1210, 1215 (Fed. Cir. 1995) ("[T]he 
existence of a general method of isolating cDNA or DNA 
molecules is essentially irrelevant to the question whether 
the specific molecules themselves would have been obvi-
ous, in the absence of other prior art that suggests the 
claimed DNAs."); In re Bell, 991 F.2d 781, 785, 26 
USPQ2d 1529, 1532 (Fed. Cir. 1993).  However, it may be 
proper to apply "methodology in rejecting product claims 
under 35 U.S.C. 103, depending on the particular facts of 
the case, the manner and context in which methodology 
applies, and the overall logic of the rejection." Ex parte 
Goldgaber, 41 USPQ2d 1172, 1176 (Bd. Pat. App. & Inter. 
1996).

PRESUMPTION OF OBVIOUSNESS BASED ON 
STRUCTURAL SIMILARITY IS OVERCOME 
WHERE THERE IS NO REASONABLE EXPECTA-
TION OF SIMILAR PROPERTIES

The presumption of obviousness based on a reference 
disclosing structurally similar compounds may be over-
come where there is evidence showing there is no reason-
able expectation of similar properties in structurally similar 
compounds. In re May, 574 F.2d 1082, 197 USPQ 601 
(CCPA 1978) (appellant produced sufficient evidence to 
establish a substantial degree of unpredictability in the per-
tinent art area, and thereby rebutted the presumption that 
structurally similar compounds have similar properties); In 
re Schechter, 205 F.2d 185, 98 USPQ 144 (CCPA 1953). 
See also Ex parte Blattner, 2 USPQ2d 2047 (Bd. Pat. App. 
& Inter. 1987) (Claims directed to compounds containing a 
7-membered ring were rejected as prima facie obvious over 
a reference which taught 5- and 6-membered ring 
homologs of the claimed compounds. The Board reversed 
the rejection because the prior art taught that the com-
pounds containing a 5-membered ring possessed the oppo-
site utility of the compounds containing the 6-membered 
ring, undermining the examiner's asserted prima facie case 
arising from an expectation of similar results in the claimed 
compounds which contain a 7-membered ring.). 

IF PRIOR ART COMPOUNDS HAVE NO UTILITY, 
OR UTILITY ONLY AS INTERMEDIATES, 
CLAIMED STRUCTURALLY SIMILAR COM-
POUNDS MAY NOT BE PRIMA FACIE OBVIOUS 
OVER THE PRIOR ART 

If the prior art does not teach any specific or significant 
utility for the disclosed compounds, then the prior art is not 
sufficient to render structurally similar claims prima facie 
obvious because there is no motivation for one of ordinary 
skill in the art to make the reference compounds, much less 
any structurally related compounds. In re Stemniski, 444 
F.2d 581, 170 USPQ 343 (CCPA 1971). 

Where structurally similar "prior art compounds `cannot 
be regarded as usefu' for the sole use disclosed [by the ref-
erence], . . . a person having ordinary skill in the art would 
lack the `necessary impetus' to make the claimed com-
pounds." In re Albrecht, 514 F.2d 1389, 1396,  185 USPQ 
585, 590 (CCPA 1975) (prior art reference studied the local 
anesthetic activity of various compounds, and taught that 
compounds structurally similar to those claimed were irri-
tating to human skin and therefore "cannot be regarded as 
useful anesthetics." 514 F.2d at 1393, 185 USPQ at 587).

Similarly, if the prior art merely discloses compounds as 
intermediates in the production of a final product, one of 
ordinary skill in the art would not have been motivated to 
stop the reference synthesis and investigate the intermedi-
ate compounds with an expectation of arriving at claimed 
compounds which have different uses. In re Lalu, 747 F.2d 
703, 223 USPQ 1257 (Fed. Cir. 1984). 

PRIMA FACIE CASE REBUTTABLE BY EVIDENCE 
OF SUPERIOR OR UNEXPECTED RESULTS

A prima facie case of obviousness based on structural 
similarity is rebuttable by proof that the claimed com-
pounds possess unexpectedly advantageous or superior 
properties. In re Papesch, 315 F.2d 381, 137 USPQ 43 
(CCPA 1963) (Affidavit evidence which showed that 
claimed triethylated compounds possessed anti-inflamma-
tory activity whereas prior art trimethylated compounds did 
not was sufficient to overcome obviousness rejection based 
on the homologous relationship between the prior art and 
claimed compounds.); In re Wiechert, 370 F.2d 927, 152 
USPQ 247 (CCPA 1967) (a 7-fold improvement of activity 
over the prior art held sufficient to rebut prima facie obvi-
ousness based on close structural similarity). 

However, a claimed compound may be obvious because 
it was suggested by, or structurally similar to, a prior art 
compound even though a particular benefit of the claimed 
compound asserted by patentee is not expressly disclosed 
in the prior art. It is the differences in fact in their respec-
tive properties which are determinative of nonobviousness. 
If the prior art compound does in fact possess a particular 
benefit, even though the benefit  is not recognized in the 
prior art, applicant's recognition of the benefit is not in 
itself sufficient to distinguish the claimed compound from 
the prior art. In re Dillon, 919 F.2d 688, 16 USPQ2d 1897 
(Fed. Cir. 1991).

See  MPEP ? 716.02 - ? 716.02(g) for a discussion of 
evidence alleging unexpectedly advantageous or superior 
results.

2145	Consideration of Applicant's Rebuttal 
Arguments

I.	ARGUMENT DOES NOT REPLACE EVI-
DENCE WHERE EVIDENCE IS NECESSARY

Attorney argument is not evidence unless it is an admis-
sion, in which case, an examiner may use the admission in 
making a rejection. See MPEP ? 2129 and ? 2144.03 for a 
discussion of admissions as prior art. 

The arguments of counsel cannot take the place of evi-
dence in the record. In re Schulze, 346 F.2d 600, 602, 145 
USPQ 716, 718 (CCPA 1965); In re Geisler, 116 F.3d 
1465, 43 USPQ2d 1362  (Fed. Cir. 1997) ("An assertion of 
what seems to follow from common experience is just 
attorney argument and not the kind of factual evidence  that 
is required to rebut a prima facie case of obviousness."). 
See  MPEP ? 716.01(c) for examples of attorney statements 
which are not evidence and which must be supported by an 
appropriate affidavit or declaration.

II.	ARGUING ADDITIONAL ADVANTAGES OR 
LATENT PROPERTIES

Prima Facie Obviousness Is Not Rebutted by Merely 
Recognizing Additional Advantages or Latent Properties 
Present in the Prior Art

Mere recognition of latent properties in the prior art does 
not render nonobvious an otherwise known invention. In re 
Wiseman, 596 F.2d 1019, 201 USPQ 658 (CCPA 1979) 
(Claims were directed to grooved carbon disc brakes 
wherein the grooves were provided to vent steam or vapor 
during a braking action. A prior art reference taught non-
carbon disc brakes which were grooved for the purpose of 
cooling the faces of the braking members and eliminating 
dust. The court held the prior art references when combined 
would overcome the problems of dust and overheating 
solved by the prior art and would inherently overcome the 
steam or vapor cause of the problem relied upon for patent-
ability by applicants. Granting a patent on the discovery of 
an unknown but inherent function (here venting steam or 
vapor) "would remove from the public that which is in the 
public domain by virtue of its inclusion in, or obviousness 
from, the prior art." 596 F.2d at 1022, 201 USPQ at 661.);   
In re Baxter Travenol Labs., 952 F.2d 388, 21 USPQ2d 
1281 (Fed. Cir. 1991) (Appellant argued that the presence 
of DEHP as the plasticizer in a blood collection bag unex-
pectedly suppressed hemolysis and therefore rebutted any 
prima facie showing of obviousness, however the closest 
prior art utilizing a DEHP plasticized blood collection bag 
inherently achieved same result, although this fact was 
unknown in the prior art.).

"The fact that appellant has recognized another advan-
tage which would flow naturally from following the sug-
gestion of the prior art cannot be the basis for patentability 
when the differences would otherwise be obvious." Ex 
parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 
1985) (The prior art taught combustion fluid analyzers 
which used labyrinth heaters to maintain the samples at a 
uniform temperature. Although appellant showed an unex-
pectedly shorter response time was obtained when a laby-
rinth heater was employed, the Board held this advantage 
would flow naturally from following  the suggestion of the 
prior art.). See also   Lantech Inc. v. Kaufman Co. of Ohio 
Inc., 878 F.2d 1446, 12 USPQ2d 1076, 1077 (Fed. Cir. 
1989), cert. denied, 493 U.S. 1058 (1990) (unpublished - 
not citable as precedent) ("The recitation of an additional 
advantage associated with doing what the prior art suggests 
does not lend patentability to an otherwise unpatentable 
invention.").

In re Lintner, 458 F.2d 1013, 173 USPQ 560 (CCPA 
1972) and In re Dillon, 919 F.2d 688, 16 USPQ2d 1897 
(Fed. Cir. 1990) discussed in MPEP ? 2144 are also perti-
nent to this issue.

See  MPEP ? 716.02 - ? 716.02(g) for a discussion of 
declaratory evidence alleging unexpected results.

III.	ARGUING THAT PRIOR ART DEVICES ARE 
NOT PHYSICALLY COMBINABLE

"The test for obviousness is not whether the features of a 
secondary reference may be bodily incorporated into the 
structure of the primary reference. . . . Rather, the test is 
what the combined teachings of those references would 
have suggested to those of ordinary skill in the art." In re 
Keller, 642 F.2d 413, 425, 208 USPQ 871, 881 (CCPA 
1981). See also In re Sneed, 710 F.2d 1544, 1550, 218 
USPQ 385, 389 (Fed. Cir. 1983) ("[I]t is not necessary that 
the inventions of the references be physically combinable 
to render obvious the invention under review."); and In re 
Nievelt, 482 F.2d 965, 179 USPQ 224, 226 (CCPA 1973) 
("Combining the teachings of references does not involve 
an ability to combine their specific structures.").

However, the claimed combination cannot change the 
principle of operation of the primary reference or render the 
reference inoperable for its intended purpose. See  MPEP 
? 2143.01. 

IV.	ARGUING AGAINST REFERENCES INDI-
VIDUALLY 

One cannot show nonobviousness by attacking refer-
ences individually where the rejections are based on combi-
nations of references. In re Keller, 642 F.2d 413, 208 USPQ 
871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 
231 USPQ 375 (Fed. Cir. 1986).

V.	ARGUING ABOUT THE NUMBER OF 
REFERENCES COMBINED

Reliance on a large number of references in a rejection 
does not, without more, weigh against the obviousness of 
the claimed invention. In re Gorman, 933 F.2d 982, 18 
USPQ2d 1885 (Fed. Cir. 1991) (Court affirmed a rejection 
of a detailed claim to a candy sucker shaped like a thumb 
on a stick based on thirteen prior art references.).

VI.	ARGUING LIMITATIONS WHICH ARE NOT 
CLAIMED 

Although the claims are interpreted in light of the speci-
fication, limitations from the specification are not read into 
the claims. In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 
1057 (Fed. Cir. 1993) (Claims to a superconducting magnet 
which generates a "uniform magnetic field" were not lim-
ited to the degree of magnetic field uniformity required for 
Nuclear Magnetic Resonance (NMR) imaging. Although 
the specification disclosed that the claimed magnet may be 
used in an NMR apparatus, the claims were not so lim-
ited.); Constant v. Advanced Micro-Devices, Inc., 848 F.2d 
1560, 1571-72, 7 USPQ2d 1057, 1064-1065 (Fed. Cir.), 
cert. denied, 488 U.S. 892 (1988) (Various limitations on 
which appellant relied were not stated in the claims; the 
specification did not provide evidence indicating these lim-
itations must be read into the claims to give meaning to the 
disputed terms.); Ex parte McCullough, 7 USPQ2d 1889, 
1891 (Bd. Pat. App. & Inter. 1987) (Claimed electrode was 
rejected as obvious despite assertions that electrode func-
tions differently than would be expected when used in non-
aqueous battery since "although the demonstrated results 
may be germane to the patentability of a battery containing 
appellant's electrode, they are not germane to the patent-
ability of the invention claimed on appeal.").

See MPEP ? 2111 - ? 2116.01, for additional case law 
relevant to claim interpretation.

VII.	ARGUING ECONOMIC INFEASIBILITY 

The fact that a combination would not be made by busi-
nessmen for economic reasons does not mean that a person 
of ordinary skill in the art would not make the combination 
because of some technological incompatibility. In re Far-
renkopf, 713 F.2d 714, 219 USPQ 1 (Fed. Cir. 1983) (Prior 
art reference taught that addition of inhibitors to radioim-
munoassay is the most convenient, but costliest solution to 
stability problem. The court held that the additional 
expense associated with the addition of inhibitors would 
not discourage one of ordinary skill in the art from seeking 
the convenience expected therefrom.).

VIII.	ARGUING ABOUT THE AGE OF REFER-
ENCES 

"The mere age of the references is not persuasive of the 
unobviousness of the combination of their teachings, absent 
evidence that, notwithstanding knowledge of the refer-
ences, the art tried and failed to solve the problem." In re 
Wright, 569 F.2d 1124, 1127, 193 USPQ 332, 335 (CCPA 
1977) (100 year old patent was properly relied upon in a 
rejection based on a combination of references.). See also 
Ex parte Meyer, 6 USPQ2d 1966 (Bd. Pat. App. & Inter. 
1988) (length of time between the issuance of prior art pat-
ents relied upon (1920 and 1976) was not persuasive of 
unobviousness).

IX.	ARGUING THAT PRIOR ART IS NONANAL-
OGOUS 

A prior art reference is analogous if the reference is in 
the field of applicant's endeavor or, if not, the reference is 
reasonably pertinent to the particular problem with which 
the inventor was concerned. In re Oetiker, 977 F.2d 1443, 
1446, 24 USPQ2d 1443, 1445 (Fed. Cir. 1992). 

See  MPEP ? 2141.01(a) for case law pertaining to anal-
ogous art.

X.	ARGUING IMPROPER RATIONALES FOR 
COMBINING REFERENCES

A.	Impermissible Hindsight

Applicants may argue that the examiner's conclusion of 
obviousness is based on improper hindsight reasoning. 
However, "[a]ny judgement on obviousness is in a sense 
necessarily a reconstruction based on hindsight reasoning, 
but so long as it takes into account only knowledge which 
was within the level of ordinary skill in the art at the time 
the claimed invention was made and does not include 
knowledge gleaned only from applicant's disclosure, such a 
reconstruction is proper." In re McLaughlin 443 F.2d 1392, 
1395, 170 USPQ 209, 212 (CCPA 1971).

B.	Obvious To Try Rationale

An applicant may argue the examiner is applying an 
improper "obvious to try" rationale in support of an obvi-
ousness rejection.

"The admonition that `obvious to try' is not the standard 
under ? 103 has been directed mainly at two kinds of error. 
In some cases, what would have been `obvious to try' 
would have been to vary all parameters or try each of 
numerous possible choices until one possibly arrived at a 
successful result, where the prior art gave either no indica-
tion of which parameters were critical or no direction as to 
which of many possible choices is likely to be successful. . 
. . In others, what was `obvious to try' was to explore a new 
technology or general approach that seemed to be a promis-
ing field of experimentation, where the prior art gave only 
general guidance as to the particular form of the claimed 
invention or how to achieve it." In re O'Farrell, 853 F.2d 
894, 903, 7 USPQ2d 1673, 1681 (Fed. Cir. 1988) (citations 
omitted) (The court held the claimed method would have 
been obvious over the prior art relied upon because one ref-
erence contained a detailed enabling methodology, a sug-
gestion to modify the prior art to produce the claimed 
invention, and evidence suggesting the modification would 
be successful.). See the cases cited in O'Farrell for exam-
ples of decisions where the court discussed an improper 
"obvious to try" approach. See also In re Eli Lilly & Co., 
902 F.2d 943, 14 USPQ2d 1741 (Fed. Cir. 1990) and In re 
Ball Corp., 925 F.2d 1480, 18 USPQ2d 1491 (Fed. Cir. 
1991) (unpublished) for examples of cases where appel-
lants argued that an improper "obvious to try" standard was 
applied, but the court found that there was proper motiva-
tion to modify the references. 

C.	Lack of Suggestion To Combine References

As discussed in MPEP ? 2143.01, there must be some 
suggestion or motivation, either in the references them-
selves or in the knowledge generally available to one of 
ordinary skill in the art, to modify or combine reference 
teachings. The Federal Circuit has produced a number of 
decisions overturning obviousness rejections due to a lack 
of suggestion in the prior art of the desirability of combin-
ing references, as discussed in the aforementioned section.

D.	References Teach Away from the Invention or 
Render Prior Art Unsatisfactory for Intended 
Purpose

In addition to the material below, see MPEP ? 2141.02 
(prior art must be considered in its entirety, including dis-
closures that teach away from the claims) and MPEP 
? 2143.01 (proposed modification cannot render the prior 
art unsatisfactory for its intended purpose or change the 
principle of operation of a reference).

1.	The Nature of the Teaching Is Highly Relevant

A prior art reference that "teaches away" from the 
claimed invention is a significant factor to be considered in 
determining obviousness; however, "the nature of the 
teaching is highly relevant and must be weighed in sub-
stance. A known or obvious composition does not become 
patentable simply because it has been described as some-
what inferior to some other product for the same use." In re 
Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. 
Cir. 1994) (Claims were directed to an epoxy resin based 
printed circuit material. A prior art reference disclosed a 
polyester-imide resin based printed circuit material, and 
taught that although epoxy resin based materials have 
acceptable stability and some degree of flexibility, they are 
inferior to polyester-imide resin based materials. The court 
held the claims would have been obvious over the prior art 
because the reference taught epoxy resin based material 
was useful for applicant's purpose, applicant did not distin-
guish the claimed epoxy from the prior art epoxy, and 
applicant asserted no discovery beyond what was known to 
the art.).

2.	References Cannot Be Combined Where Refer-
ence Teaches Away from Their Combination

It is improper to combine references where the refer-
ences teach away from their combination. In re Grasselli, 
713 F.2d 731, 743, 218 USPQ 769, 779 (Fed. Cir. 1983) 
(The claimed catalyst which contained both iron and an 
alkali metal was not suggested by the combination of a ref-
erence which taught the interchangeability of antimony and 
alkali metal with the same beneficial result, combined with 
a reference expressly excluding antimony from, and adding 
iron to, a catalyst.). 

3.	Proceeding Contrary to Accepted Wisdom Is Evi-
dence of Nonbviousness

The totality of the prior art must be considered, and pro-
ceeding contrary to accepted wisdom in the art is evidence 
of nonobviousness.   In re Hedges, 783 F.2d 1038, 228 
USPQ 685 (Fed. Cir. 1986) (Applicant's claimed process 
for sulfonating diphenyl sulfone at a temperature above 
127?C was contrary to accepted wisdom because the prior 
art as a whole suggested using lower temperatures for opti-
mum results as evidenced by charring, decomposition, or 
reduced yields at higher temperatures.).

Furthermore, "[k]nown disadvantages in old devices 
which would naturally discourage search for new inven-
tions may be taken into account in determining obvious-
ness." United States v. Adams, 383 U.S. 39, 52, 148 USPQ 
479, 484 (1966).

XI.	FORM PARAGRAPHS 

See  MPEP ? 707.07 for Form Paragraphs 7.37 through 
7.38 which may be used where applicant's arguments are 
not persuasive or are moot.

2146	35 U.S.C. 103(c) [R-1]

35 U.S.C. 103.  Conditions of patentability; non-obvious subject 
matter.

*****

**

(c)	>Subject matter developed by another person, which qualifies 
as prior art only under one or more subsections (e), (f), and (g) of section 
102 of this title, shall not preclude patentability under this section where 
the subject matter and the claimed invention were, at the time the inven-
tion was made, owned by the same person or subject to an obligation of 
assignment to the same person.<

>Effective November 29, 1999,< 35 U.S.C. 103(c) pro-
vides that subject matter developed by another which quali-
fies as "prior art" only under >one or more of subsections<   
35 U.S.C. 102>(e),< (f) *>and< (g) is not to be considered 
when determining whether an invention sought to be pat-
ented is obvious under  35 U.S.C. 103, provided the subject 
matter and the claimed invention were commonly owned at 
the time the invention was made. 35 U.S.C. 103(c) applies 
only to subject matter which qualifies as prior art under 
35 U.S.C. 103; it does not affect subject matter which qual-
ifies as prior art under  35 U.S.C. 102, i.e., anticipatory 
prior art. See MPEP ? 706.02(l) >- ? 706.02(l)(3).< 

2161	Three Separate Requirements for 
Specification Under 35 U.S.C. 112,  
First Paragraph 

THE SPECIFICATION MUST INCLUDE A WRIT-
TEN DESCRIPTION OF THE INVENTION, 
ENABLEMENT, AND BEST MODE OF CARRYING 
OUT THE CLAIMED INVENTION

The first paragraph of  35 U.S.C. 112 provides:

The specification shall contain a written description of the inven-
tion, and of the manner and process of making and using it, in 
such full, clear, concise, and exact terms as to enable any person 
skilled in the art to which it pertains, or with which it is most 
nearly connected, to make and use the same, and shall set forth 
the best mode contemplated by the inventor of carrying out his 
invention. (emphasis added).

This section of the statute requires that the specification 
include the following:

(A)	A written description of the invention;

(B)	The manner and process of making and using the 
invention (the enablement requirement); and

(C)	The best mode contemplated by the inventor of 
carrying out his invention.

THE THREE REQUIREMENTS ARE SEPARATE 
AND DISTINCT FROM EACH OTHER

The written description requirement is separate and dis-
tinct from the enablement requirement. In re Barker, 559 
F.2d 588, 194 USPQ 470 (CCPA 1977), cert. denied, 434 
U.S. 1064 (1978); Vas-Cath, Inc. v. Mahurkar, 935 F.2d 
1555, 1562, 19 USPQ2d 1111, 1115 (Fed. Cir. 1991) 
(While acknowledging that some of its cases concerning 
the written description requirement and the enablement 
requirement are confusing, the Federal Circuit reaffirmed 
that under 35 U.S.C. 112, first paragraph, the written 
description requirement is separate and distinct from the 
enablement requirement and gave an example thereof.). An 
invention may be described without the disclosure being 
enabling (e.g., a chemical compound for which there is no 
disclosed or apparent method of making), and a disclosure 
could be enabling without describing the invention (e.g., a 
specification describing a method of making and using a 
paint composition made of functionally defined ingredients 
within broad ranges would be enabling for formulations 
falling within the description but would not describe any 
specific formulation). See In re Armbruster, 512 F.2d 676, 
677, 185 USPQ 152, 153 (CCPA 1975) ("[A] specification 
which `describes' does not necessarily also `enable' one 
skilled in the art to make or use the claimed invention."). 
Best mode is a separate and distinct requirement from the 
enablement requirement. In re Newton, 414 F.2d 1400, 163 
USPQ 34 (CCPA 1969).

2162	Policy Underlying 35 U.S.C. 112, First 
Paragraph

To obtain a valid patent, a patent application must be 
filed that contains a full and clear disclosure of the inven-
tion in the manner prescribed by  35 U.S.C. 112, first para-
graph. The requirement for an adequate disclosure ensures 
that the public receives something in return for the exclu-
sionary rights that are granted to the inventor by a patent. 
The grant of a patent helps to foster and enhance the devel-
opment and disclosure of new ideas and the advancement 
of scientific knowledge. Upon the grant of a patent in the 
U.S., information contained in the patent becomes a part of 
the information available to the public for further research 
and development, subject only to the patentee's right to 
exclude others during the life of the patent.

In exchange for the patent rights granted,  35 U.S.C. 112, 
first paragraph sets forth the minimum requirements for the 
quality and quantity of information that must be contained 
in the patent to justify the grant. As will be discussed in 
more detail below, the patentee must disclose in the patent 
sufficient information to put the public in possession of the 
invention and to enable those skilled in the art to make and 
use the invention and must not conceal from the public the 
best way of practicing the invention that was known to the 
patentee at the time of filing the patent application. Failure 
to fully comply with the disclosure requirements could 
result in the denial of a patent, or in a holding of invalidity 
of an issued patent.

2163	The Written Description Requirement

The written description requirement has several policy 
objectives. "[T]he `essential goal' of the description of the 
invention requirement is to clearly convey the information 
that an applicant has invented the subject matter which is 
claimed." In re Barker, 559 F.2d 588, 592 n.4, 194 USPQ 
470, 473 n.4 (CCPA 1977), cert. denied, 434 U.S. 1064 
(1978). Another objective is to put the public in possession 
of what the applicant claims as the invention so that the 
public may ascertain if the patent applicant claims anything 
that is in common use, or already known. Evans v. Eaton, 
20 U.S. (7 Wheat.) 356 (1822). 

An applicant's specification must convey with reason-
able clarity to those skilled in the art that, as of the filing 
date sought, he or she was in possession of the invention, 
i.e., whatever is now claimed. Vas-Cath, Inc. v. Mahurkar, 
935 F.2d 1555, 1563-64, 19 USPQ2d 1111, 1117 (Fed. Cir. 
1991). The written description requirement prevents an 
applicant from claiming subject matter that was not 
described in the application as filed, and the proscription 
against the introduction of new matter in a patent applica-
tion (35 U.S.C. 132 and 251) serves to prevent an applicant 
from adding to the informational content of a patent appli-
cation after it is filed.

2163.01	Support for the Claimed Subject 
Matter in Disclosure

A written description requirement issue generally 
involves the question of whether the subject matter of a 
claim is supported by [conforms to] the disclosure of an 
application as filed. If the examiner concludes that the 
claimed subject matter is not supported [described] in an 
application as filed, this would result in a rejection of the 
claim on the ground of a lack of written description under  
35 U.S.C. 112, first paragraph or denial of the benefit of the 
filing date of a previously filed application. The claim 
should not be rejected or objected to on the ground of new 
matter. As framed by the court in In re Rasmussen, 650 F.2d 
1212, 211 USPQ 323 (CCPA 1981), the concept of new 
matter is properly employed as a basis for objection to 
amendments to the abstract, specification or drawings 
attempting to add new disclosure to that originally pre-
sented. While the test or analysis of description require-
ment and new matter issues is the same, the examining 
procedure and statutory basis for addressing these issues 
differ. See  MPEP ? 2163.06.

2163.02	Standard for Determining 
Compliance With the Written 
Description Requirement

The courts have described the essential question to be 
addressed in a description requirement issue in a variety of 
ways. An objective standard for determining compliance 
with the written description requirement is, "does the 
description clearly allow persons of ordinary skill in the art 
to recognize that he or she invented what is claimed." In re 
Gosteli, 872 F.2d 1008, 1012, 10 USPQ2d 1614, 1618 
(Fed. Cir. 1989). Under Vas-Cath, Inc. v.  Mahurkar, 935 
F.2d 1555, 1563-64, 19 USPQ2d 1111, 1117 (Fed. Cir. 
1991), to satisfy the written description requirement, an 
applicant must convey with reasonable clarity to those 
skilled in the art that, as of the filing date sought, he or she 
was in possession of the invention, and that the invention, 
in that context, is whatever is now claimed. The test for suf-
ficiency of support in a parent application is whether the 
disclosure of the application relied upon "reasonably con-
veys to the artisan that the inventor had possession at that 
time of the later claimed subject matter." Ralston Purina 
Co. v. Far-Mar-Co., Inc., 772 F.2d 1570, 1575, 227 USPQ 
177, 179 (Fed. Cir. 1985) (quoting   In re Kaslow, 707 F.2d 
1366, 1375, 217 USPQ 1089, 1096 (Fed. Cir. 1983)).

Whenever the issue arises, the fundamental factual 
inquiry is whether a claim defines an invention that is 
clearly conveyed to those skilled in the art at the time the 
application was filed. The subject matter of the claim need 
not be described literally (i.e., using the same terms or in 
haec verba) in order for the disclosure to satisfy the 
description requirement. If a claim is amended to include 
subject matter, limitations, or terminology not present in 
the application as filed, involving a departure from, addi-
tion to, or deletion from the disclosure of the application as 
filed, the examiner should conclude that the claimed sub-
ject matter is not described in that application. This conclu-
sion will result in the rejection of the claims affected under 
35 U.S.C.112, first paragraph - description requirement, or 
denial of the benefit of the filing date of a previously filed 
application, as appropriate.

2163.03	Typical Circumstances Where 
Adequate Written Description 
Issue Arises [R-1]

A description requirement issue can arise in a number of 
different circumstances where it must be determined 
whether the subject matter of a new or amended claim is 
supported in an application as filed. The following circum-
stances are typical:

I.	AMENDMENT AFFECTING A CLAIM

An amendment to the claims or the addition of a new 
claim must be supported by the description of the invention 
in the application as filed. In re Wright, 866 F.2d 422, 9 
USPQ2d 1649 (Fed. Cir. 1989). Original claims constitute 
their own description. In re Koller, 613 F.2d 819, 204 
USPQ 702 (CCPA 1980). An amendment to the specifica-
tion (e.g., a change in the definition of a term used both in 
the specification and claim) may indirectly affect a claim 
even though no actual amendment is made to the claim. 

II.	RELIANCE ON FILING DATE OF PARENT 
APPLICATION UNDER 35 U.S.C. 120

Under 35 U.S.C. 120, the claims in a U.S. application are 
entitled to the benefit of the filing date of an earlier filed 
U.S. application if the subject matter of the claim is dis-
closed in the manner provided by 35 U.S.C. 112, first para-
graph in the earlier filed application. In re Scheiber, 587 
F.2d 59, 199 USPQ 782 (CCPA 1978).

III.	RELIANCE ON PRIORITY UNDER  35 U.S.C. 
119

Under 35 U.S.C. 119 (a) or (e), the claims in a U.S. 
application are entitled to the benefit of a foreign priority 
date or the filing date of a provisional application if the cor-
responding foreign application or provisional application 
supports the claims in the manner required by 35 U.S.C. 
112, first paragraph. In re Ziegler, 992 F.2d 1197, 1200, 26 
USPQ2d 1600, 1603 (Fed. Cir. 1993);   Kawai v. Metlesics, 
480 F.2d 880, 178 USPQ 158 (CCPA 1973); In re Gosteli, 
872 F.2d 1008, 10 USPQ2d 1614 (Fed. Cir. 1989).

IV.	SUPPORT FOR A CLAIM CORRESPONDING 
TO A COUNT IN AN INTERFERENCE

**>In an interference proceeding, the claim correspond-
ing to a count must be supported by the specification in the 
manner provided by 35 U.S.C.  112, first paragraph. Fields 
v. Conover, 443 F.2d 1386, 170 USPQ 276 (CCPA 1971)(A 
broad generic disclosure to a class of compounds was not a 
sufficient written description of a specific compound 
within the class.). Furthermore, when a party to an interfer-
ence seeks the benefit of an earlier-filed U.S. patent appli-
cation, the earlier application must meet the requirements 
of 35 U.S.C.  112, first paragraph for the subject matter of 
the count. Hyatt v. Boone, 146 F.3d 1348, 1352, 47 
USPQ2d 1128, 1130 (Fed. Cir. 1998).<

2163.04	Burden on the Examiner With 
Regard to the Written Description  
Requirement

The inquiry into whether the description requirement is 
met must be determined on a case-by-case basis and is a 
question of fact. In re Wertheim, 541 F.2d 257, 262, 191 
USPQ 90, 96 (CCPA 1976). The examiner has the initial 
burden of presenting evidence or reasons why persons 
skilled in the art would not recognize in an applicant's dis-
closure a description of the invention defined by the claims. 
541 F.2d at 265, 191 USPQ at 98. See also Ex parte Soren-
son, 3 USPQ2d 1462, 1463 (Bd. Pat. App. & Inter. 1987). 

I.	STATEMENT OF REJECTION REQUIRE-
MENTS

Any time an examiner bases a rejection of a claim or the 
denial of the effect of a filing date of a previously filed 
application on the lack of a written description, the exam-
iner should:  (A) identify the claim limitation not described; 
and (B) provide reasons why persons skilled in the art at the 
time the application was filed would not have recognized 
the description of this limitation in the disclosure of the 
application as filed. A typical reason points out the differ-
ences between what is disclosed and what is claimed. A 
simple statement that "There does not appear to be a writ-
ten description of the claim limitation `______' in the 
application as filed." may be sufficient where the support is 
not apparent and the applicant has not pointed out where 
the limitation is supported.

II.	RESPONSE TO AMENDMENTS

If applicant amends the claims and points out where and/
or how the originally filed disclosure supports the amend-
ment(s), and the examiner finds that the disclosure does not 
reasonably convey that the inventor had possession of the 
subject matter of the amendment at the time of the filing of 
the application, the examiner has the initial burden of pre-
senting evidence or reasoning to explain why persons 
skilled in the art would not recognize in the disclosure a 
description of the invention defined by the claims. Accord-
ingly, the examiner should identify what portion(s) of the 
amendment lack support in the originally filed disclosure, 
and should fully explain the basis for the examiner's find-
ing. The examiner also should comment on the substance of 
applicant's remarks. Any affidavits attesting to what one of 
ordinary skill in the art would consider disclosed by the 
application as originally filed must be thoroughly analyzed 
and discussed in the Office action.

2163.05	Changes to the Scope of Claims

The failure to meet the written description requirement 
of 35 U.S.C. 112, first paragraph, commonly arises when 
the claims are changed after filing to either broaden or nar-
row the breadth of the claim limitations, or to alter a 
numerical range limitation or to use claim language which 
is not synonymous with the terminology used in the origi-
nal disclosure.

I.	BROADENING CLAIM

In a reissue application, a claim to a display device was 
broadened by removing the limitations directed to the spe-
cific tapered shape of the tips without violating the written 
description requirement. The shape limitation was consid-
ered to be unnecessary since the specification, as filed, did 
not describe the tapered shape as essential or critical to the 
operation or patentability of the claim. In re Peters, 723 
F.2d 891, 221 USPQ 952 (Fed. Cir. 1983). 

However, in   In re Wilder, 736 F.2d 1516, 222 USPQ 
369 (Fed. Cir. 1984), the Federal Circuit affirmed that part 
of a Board of Appeals decision rejecting reissue claims for 
a recording apparatus which omitted a limitation that 
required indexing means to scan an array of light emitting 
diodes "in synchronism" with the scanning of the record 
medium by scanning means. The court held that the generic 
invention represented by the reissue claims (i.e., covering 
scanning means and indexing means not in synchronism) 
was not supported by the original patent's disclosure in 
such a way as to indicate possession, as of the original fil-
ing date, of that generic invention.

In The Gentry Gallery, Inc. v. The Berkline Corp., 134 
F.3d 1473, 1479-80, 45 USPQ2d 1498, 1503 (Fed. Cir. 
1998), the Federal Circuit held claims to a sectional sofa 
comprising, inter alia, a console and a pair of control 
means, were invalid for failing to satisfy the written 
description requirement of 35 U.S.C. 112, first paragraph, 
where the claims were broadened by removing language 
limiting the location of the control means to the console. 
The court acknowledged that while a claim may be broader 
than the specific embodiment disclosed in the specification, 
the "claims may be no broader than the supporting disclo-
sure."  Thus, a narrow disclosure will limit claim breadth. 
Upon reading the disclosure, the court noted, "one skilled 
in the art would clearly understand that it was not only 
important, but essential to [patentee's] invention, for the 
controls to be on the console."  The court based this conclu-
sion on several factors: the fact that the disclosure provided 
for only the most minor variation in the location of the con-
trols by providing that the control "may be mounted on the 
top or side surfaces of the console rather than on the front 
wall... without departing from the invention;" the only dis-
cernable purpose for the console was to house the controls; 
the broadest original claim limited the location of the con-
trol means to the console; and, at trial, the patentee admit-
ted that he did not consider placing the controls outside the 
console until he became aware that some of his competitors 
were so locating the controls.

The benefit of foreign priority was denied in In re Gos-
teli, 872 F.2d 1008, 10 USPQ2d 1614 (Fed. Cir. 1989), 
because claims in the U.S. application were not supported 
in the foreign priority application. In the claims of the U.S. 
application, chemical compounds representing antibiotics 
were generically claimed via reference to a structure with 
varying moieties and were also claimed subgenerically in a 
Markush format. The foreign application disclosed only 2 
of the species presented in the broad generic claim and in 
the 21 compounds listed in the Markush claims. The court 
concluded that the additional subject matter in the U.S. 
application was not adequately described in the foreign 
document.

II.	NARROWING OR SUBGENERIC CLAIM

The introduction of claim changes which involve nar-
rowing the claims by introducing elements or limitations 
which are not supported by the as-filed disclosure is a vio-
lation of the written description requirement of 35 U.S.C. 
112, first paragraph. In Ex parte Ohshiro, 14 USPQ2d 1750 
(Bd. Pat. App. & Inter. 1989), the Board affirmed the rejec-
tion under 35 U.S.C. 112, first paragraph, of claims to an 
internal combustion engine which recited "at least one of 
said piston and said cylinder (head) having a recessed chan-
nel." The Board held that the application which disclosed a 
cylinder head with a recessed channel and a piston without 
a recessed channel did not specifically disclose the "spe-
cies" of a channeled piston.

While this and other cases find that recitation of an 
undisclosed species may violate the description require-
ment, a change involving subgeneric terminology may or 
may not be acceptable. Applicant was not entitled to the 
benefit of a parent filing date when the claim was directed 
to a subgenus (a specified range of molecular weight ratios) 
where the parent application contained a generic disclosure 
and a specific example that fell within the recited range 
because the court held that subgenus range was not 
described in the parent application.   In re Lukach, 442 F.2d 
967, 169 USPQ 795 (CCPA 1971). On the other hand, in Ex 
parte Sorenson, 3 USPQ2d 1462 (Bd. Pat. App. & Inter. 
1987), the subgeneric language of "aliphatic carboxylic 
acid" and "aryl carboxylic acid" did not violate the written 
description requirement because species falling within each 
subgenus were disclosed as well as the generic carboxylic 
acid. See also In re Smith, 458 F.2d 1389, 1395, 173 USPQ 
679, 683 (CCPA 1972) ("Whatever may be the viability of 
an inductive-deductive approach to arriving at a claimed 
subgenus, it cannot be said that such a subgenus is neces-
sarily described by a genus encompassing it and a species 
upon which it reads." (emphasis added)). Each case must 
be decided on its own facts in terms of what is reasonably 
communicated to those skilled in the art. In re Wilder, 736 
F.2d 1516, 1520, 222 USPQ 369, 372 (Fed. Cir. 1984). 

III.	RANGE LIMITATIONS

With respect to changing numerical range limitations, 
the analysis must take into account which ranges one 
skilled in the art would consider inherently supported by 
the discussion in the original disclosure. In the decision in 
In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976), 
the ranges described in the original specification included a 
range of "25%- 60%" and specific examples of "36%" and 
"50%." A corresponding new claim limitation to "at least 
35%" did not meet the description requirement because the 
phrase "at least" had no upper limit and caused the claim to 
read literally on embodiments outside the "25% to 60%" 
range, however a limitation to "between 35% and 60%" did 
meet the description requirement.

2163.06	Relationship of Written Description 
Requirement to New Matter [R-1]

Lack of written description is an issue that generally 
arises with respect to the subject matter of a claim. If an 
applicant amends or attempts to amend the abstract, specifi-
cation or drawings of an application, an issue of new matter 
will arise if the content of the amendment is not described 
in the application as filed. Stated another way, information 
contained in any one of the specification, claims or draw-
ings of the application as filed may be added to any other 
part of the application without introducing new matter.

There are two statutory provisions that prohibit the intro-
duction of new matter: 35 U.S.C. 132 - No amendment 
shall introduce new matter into the disclosure of the inven-
tion; and, similarly providing for a reissue application, 
35 U.S.C. 251 - No new matter shall be introduced into the 
application for reissue.

I.	TREATMENT OF NEW MATTER

**

If new subject matter is added to the disclosure, whether 
it be in the abstract, the specification, or the drawings,  the 
examiner should object to the introduction of new matter 
under 35 U.S.C. 132 or 251 as appropriate, and require 
applicant to cancel the new matter. If new matter is added 
to the claims, the examiner should reject the claims under  
35 U.S.C. 112, first paragraph - written description require-
ment. In re Rasmussen, 650 F.2d 1212, 211 USPQ 323 
(CCPA 1981). The examiner should still consider the sub-
ject matter added to the claim in making rejections based 
on prior art since the new matter rejection may be over-
come by applicant.

In an instance in which the claims have not been 
amended, per se, but the specification has been amended to 
add new matter, a rejection of the claims under 35 U.S.C. 
112, first paragraph should be made whenever any of the 
claim limitations are affected by the added material.

**

When an amendment is filed in reply to an objection or 
rejection based on 35 U.S.C. 112, first paragraph, a study of 
the entire application is often necessary to determine 
whether or not "new matter" is involved. Applicant should 
therefore specifically point out the support for any amend-
ments made to the disclosure.

II.	REVIEW OF NEW MATTER OBJECTIONS 
AND/OR REJECTIONS

A rejection of claims is reviewable by the Board of 
Patent Appeals and Interferences, whereas an objection and 
requirement to delete new matter is subject to supervisory 
review by petition under 37 CFR 1.181. If both the claims 
and specification contain new matter either directly or indi-
rectly, and there has been both a rejection and objection by 
the examiner, the issue becomes appealable and should not 
be decided by petition.

III.	CLAIMED SUBJECT MATTER NOT DIS-
CLOSED IN REMAINDER OF SPECIFICA-
TION

The claims as filed in the original specification are part 
of the disclosure and therefore, if an application as origi-
nally filed contains a claim disclosing material not dis-
closed in the remainder of the specification, the applicant 
may amend the specification to include the claimed subject 
matter. In re Benno, 768 F.2d 1340, 226 USPQ 683 (Fed. 
Cir. 1985). Form Paragraph 7.44 may be used where origi-
nally claimed subject matter lacks proper antecedent basis 
in the specification.  See  MPEP ? 608.01(o).

2163.07	Amendments to Application Which 
Are Supported in the Original  
Description

Amendments to an application which are supported in 
the original description are NOT new matter.

I.	REPHRASING

Mere rephrasing of a passage does not constitute new 
matter. Accordingly, a rewording of a passage where the 
same meaning remains intact is permissible. In re Ander-
son, 471 F.2d 1237, 176 USPQ 331 (CCPA 1973). The 
mere inclusion of dictionary or art recognized definitions 
known at the time of filing an application would not be 
considered new matter. If there are multiple definitions for 
a term and a definition is added to the application, it must 
be clear from the application as filed that applicant 
intended a particular definition, in order to avoid an issue 
of new matter and/or lack of written description.

II.	OBVIOUS ERRORS

An amendment to correct an obvious error does not con-
stitute new matter where one skilled in the art would not 
only recognize the existence of error in the specification, 
but also the appropriate correction. In re Oda, 443 F.2d 
1200, 170 USPQ 260 (CCPA 1971).

Where a non-English foreign priority document under  
35 U.S.C. 119 is of record in the application file, applicant 
may not rely on the disclosure of that document to support 
correction of an error in the pending application. Ex parte 
Bondiou, 132 USPQ 356 (Bd. App. 1961). This prohibition 
would apply regardless of the language of the foreign prior-
ity documents because a claim for priority is simply a claim 
for the benefit of an earlier filing date for subject matter 
that is common to two or more applications, and does not 
serve to incorporate the content of the priority document in 
the application in which the claim for priority is made. This 
prohibition does not apply in a situation where the original 
application is in a non-English language (37 CFR 1.52(d)), 
or where the original application explicitly incorporates a 
non-English language document by reference.

2163.07(a)	Inherent Function, Theory, or 
Advantage

By disclosing in a patent application a device that inher-
ently performs a function or has a property, operates 
according to a theory or has an advantage, a patent applica-
tion necessarily discloses that function, theory or advan-
tage, even though it says nothing explicit concerning it. The 
application may later be amended to recite the function, 
theory or advantage without introducing prohibited new 
matter. In re Reynolds, 443 F.2d 384, 170 USPQ 94 (CCPA 
1971); In re Smythe, 480 F. 2d 1376, 178 USPQ 279 (CCPA 
1973).

2163.07(b)	Incorporation by Reference

Instead of repeating some information contained in 
another document, an application may attempt to incorpo-
rate the content of another document or part thereof by ref-
erence to the document in the text of the specification. The 
information incorporated is as much a part of the applica-
tion as filed as if the text was repeated in the application, 
and should be treated as part of the text of the application as 
filed. Replacing the identified material incorporated by ref-
erence with the actual text is not new matter. See MPEP 
? 608.01(p) for Office policy regarding incorporation by 
reference.

2164	The Enablement Requirement

The enablement requirement refers to the requirement of  
35 U.S.C. 112, first paragraph that the specification 
describe how to make and how to use the invention. The 
invention that one skilled in the art must be enabled to 
make and use is that defined by the claim(s) of the particu-
lar application or patent.

The purpose of the requirement that the specification 
describe the invention in such terms that one skilled in the 
art can make and use the claimed invention is to ensure that 
the invention is communicated to the interested public in a 
meaningful way. The information contained in the disclo-
sure of an application must be sufficient to inform those 
skilled in the relevant art how to both make and use the 
claimed invention. Detailed procedures for making and 
using the invention may not be necessary if the description 
of the invention itself is sufficient to permit those skilled in 
the art to make and use the invention. A patent claim is 
invalid if it is not supported by an enabling disclosure.

The enablement requirement of 35 U.S.C. 112, first 
paragraph, is separate and distinct from the description 
requirement. Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 
1563, 19 USPQ2d 1111, 1116-17 (Fed. Cir. 1991) ("the 
purpose of the `written description' requirement is broader 
than to merely explain how to `make and use' ").  See also  
MPEP ? 2161.  Therefore, the fact that an additional limita-
tion to a claim may lack descriptive support in the disclo-
sure as originally filed does not necessarily mean that the 
limitation is also not enabled.  In other words, the statement 
of a new limitation in and of itself may enable one skilled 
in the art to make and use the claim containing that limita-
tion even though that limitation may not be described in the 
original disclosure.  Consequently, such limitations must be 
analyzed for both enablement and description using their 
separate and distinct criteria.

Furthermore, when the subject matter is not in the speci-
fication portion of the application as filed but is in the 
claims, the limitation in and of itself may enable one skilled 
in the art to make and use the claim containing the limita-
tion.  When claimed subject matter is only presented in the 
claims and not in the specification portion of the applica-
tion, the specification should be objected to for lacking the 
requisite support for the claimed subject matter using Form 
Paragraph 7.44. See  MPEP ? 2163.06.  This is an objection 
to the specification only and enablement issues should be 
treated separately.

2164.01	Test of Enablement

Any analysis of whether a particular claim is supported 
by the disclosure in an application requires a determination 
of whether that disclosure, when filed, contained sufficient 
information regarding the subject matter of the claims as to 
enable one skilled in the pertinent art to make and use the 
claimed invention. The standard for determining whether 
the specification meets the enablement requirement was 
cast in the Supreme Court decision of Mineral Separation 
v. Hyde, 242 U.S. 261, 270 (1916) which postured the ques-
tion: is the experimentation needed to practice the inven-
tion undue or unreasonable?  That standard is still the one 
to be applied. In re Wands, 858 F.2d 731, 737, 8 USPQ2d 
1400, 1404 (Fed. Cir. 1988).  Accordingly, even though the 
statute does not use the term "undue experimentation," it 
has been interpreted to require that the claimed invention 
be enabled so that any person skilled in the art can make 
and use the invention without undue experimentation. In re 
Wands, 858 F.2d at 737, 8 USPQ2d at 1404 (Fed. Cir. 
1988).  See also United States v. Telectronics, Inc., 857 F.2d 
778, 785, 8 USPQ2d 1217, 1223 (Fed. Cir. 1988) ("The test 
of enablement is whether one reasonably skilled in the art 
could make or use the invention from the disclosures in the 
patent coupled with information known in the art without 
undue experimentation."). A patent need not teach, and 
preferably omits, what is well known in the art.  In re Buch-
ner,  929 F.2d 660, 661, 18 USPQ2d 1331, 1332 (Fed. Cir. 
1991); Hybritech,  Inc. v. Monoclonal Antibodies, Inc., 802 
F.2d 1367, 1384, 231 USPQ 81, 94 (Fed. Cir. 1986), cert. 
denied, 480 U.S. 947 (1987); and Lindemann Maschinen-
fabrik GMBH v. American Hoist & Derrick Co., 730 F.2d  
1452, 1463,  221 USPQ 481, 489 (Fed. Cir. 1984). Deter-
mining enablement is a question of law based on underly-
ing factual findings. In re Vaeck, 947 F.2d 488, 495, 20 
USPQ2d 1438, 1444 (Fed. Cir. 1991);  Atlas Powder Co. v. 
E.I. du Pont de Nemours & Co., 750 F.2d 1569, 1576, 224 
USPQ 409, 413 (Fed. Cir. 1984).

UNDUE EXPERIMENTATION

The fact that experimentation may be complex does not 
necessarily make it undue, if the art typically engages in 
such experimentation. In re Certain Limited-Charge Cell 
Culture Microcarriers, 221 USPQ 1165, 1174 (Int'l Trade 
Comm'n 1983),   aff'd. sub nom., Massachusetts Institute of 
Technology v. A.B. Fortia, 774 F.2d 1104, 227 USPQ 428 
(Fed. Cir. 1985). See also In re Wands, 858 F.2d at 737, 8 
USPQ2d at 1404. The test of enablement is not whether 
any experimentation is necessary, but whether, if experi-
mentation is necessary, it is undue. In re Angstadt, 537 F.2d 
498, 504, 190 USPQ 214, 219 (CCPA 1976). 

2164.01(a)	Undue Experimentation Factors

There are many factors to be considered when determin-
ing whether there is sufficient evidence to support a deter-
mination that a disclosure does not satisfy the enablement 
requirement and whether any necessary experimentation is 
"undue."  These factors include, but are not limited to:  

(A)	The breadth of the claims; 

(B)	The nature of the invention;

(C)	The state of the prior art;

(D)	The level of one of ordinary skill;

(E)	The level of predictability in the art;

(F)	The amount of direction provided by the inventor;

(G)	The existence of working examples; and 

(H)	The quantity of experimentation needed to make 
or use the invention based on the content of the disclosure.  

In re Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 
(Fed. Cir. 1988) (reversing the PTO's determination that 
claims directed to methods for detection of hepatitis B sur-
face antigens did not satisfy the enablement requirement).  
In Wands, the court noted that there was no disagreement as 
to the facts, but merely a disagreement as to the interpreta-
tion of the data and the conclusion to be made from the 
facts.  In re Wands, 858 F.2d at 736-40, 8 USPQ2d at 1403-
07.  The Court held that the specification was enabling with 
respect to the claims at issue and found that "there was con-
siderable direction and guidance" in the specification; there 
was "a high level of skill in the art at the time the applica-
tion was filed;" and "all of the methods needed to practice 
the invention were well known."  858 F.2d at 740, 8 
USPQ2d at 1406.  After considering all the factors related 
to the enablement issue, the court concluded that "it would 
not require undue experimentation to obtain antibodies 
needed to practice the claimed invention." Id., 8 USPQ2d at 
1407.

It is improper to conclude that a disclosure is not 
enabling based on an analysis of only one of the above fac-
tors while ignoring one or more of the others. The exam-
iner's analysis must consider all the evidence related to 
each of these factors, and any conclusion of nonenablement 
must be based on the evidence as a whole. 858 F.2d at 737, 
740, 8 USPQ2d  at 1404, 1407.

A conclusion of lack of enablement means that, based on 
the evidence regarding each of the above factors, the speci-
fication, at the time the application was filed, would not 
have taught one skilled in the art how to make and/or use 
the full scope of the claimed invention without undue 
experimentation. In re Wright, 999 F.2d 1557,1562, 27 
USPQ2d 1510, 1513 (Fed. Cir. 1993).

The determination that "undue experimentation" would 
have been needed to make and use the claimed invention is 
not a single, simple factual determination.  Rather, it is a 
conclusion reached by weighing all the above noted factual 
considerations. In re Wands, 858 F.2d at 737, 8 USPQ2d at 
1404.  These factual considerations are discussed more 
fully in MPEP ? 2164.08 (scope or breadth of the claims), 
? 2164.05(a) (nature of the invention and state of the prior 
art), ? 2164.05(b) (level of one of ordinary skill), ? 2164.03 
(level of predictability in the art and amount of direction 
provided by the inventor), ? 2164.02 (the existence of 
working examples) and ? 2164.06 (quantity of experimen-
tation needed to make or use the invention based on the 
content of the disclosure).

2164.01(b)	How to Make the Claimed 
Invention

As long as the specification discloses at least one method 
for making and using the claimed invention that bears a 
reasonable correlation to the entire scope of the claim, then 
the enablement requirement of 35 U.S.C. 112 is satisfied. In 
re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 (CCPA 
1970).  Failure to disclose other methods by which the 
claimed invention may be made does not render a claim 
invalid under 35 U.S.C. 112. Spectra-Physics, Inc. v. 
Coherent, Inc., 827 F.2d 1524, 1533, 3 USPQ2d 1737, 1743 
(Fed. Cir.), cert. denied, 484 U.S. 954 (1987).

Naturally, for unstable and transitory chemical interme-
diates, the "how to make" requirement does not require that 
the applicant teach how to make the claimed product in sta-
ble, permanent or isolatable form. In re Breslow, 616 F.2d 
516, 521, 205 USPQ 221, 226 (CCPA 1980).

A key issue that can arise when determining whether the 
specification is enabling is whether the starting materials or 
apparatus necessary to make the invention are available. In 
the biotechnical area, this is often true when the product or 
process requires a particular strain of microorganism and 
when the microorganism is available only after extensive 
screening.

The Court in In re Ghiron, 442 F.2d 985, 991, 169 USPQ 
723, 727 (CCPA 1971), made clear that if the practice of a 
method requires a particular apparatus, the application must 
provide a sufficient disclosure of the apparatus if the appa-
ratus is not readily available. The same can be said if cer-
tain chemicals are required to make a compound or practice 
a chemical process. In re Howarth, 654 F.2d 103, 105, 210 
USPQ 689, 691 (CCPA 1981).

2164.01(c)	How to Use the Claimed Invention 

If a statement of utility in the specification contains 
within it a connotation of how to use, and/or the art recog-
nizes that standard modes of administration are known and 
contemplated, 35 U.S.C. 112 is satisfied. In re Johnson, 
282 F.2d 370, 373, 127 USPQ 216, 219 (CCPA 1960); In re 
Hitchings, 342 F.2d 80, 87, 144 USPQ 637, 643 (CCPA 
1965). See also In re Brana, 51 F.2d 1560, 1566, 34 
USPQ2d 1437,  1441 (Fed. Cir. 1993).

For example, it is not necessary to specify the dosage or 
method of use if it is known to one skilled in the art that 
such information could be obtained without undue experi-
mentation. If one skilled in the art, based on knowledge of 
compounds having similar physiological or biological 
activity, would be able to discern an appropriate dosage or 
method of use without undue experimentation, this would 
be sufficient to satisfy 35 U.S.C. 112, first paragraph. The 
applicant need not demonstrate that the invention is com-
pletely safe. See also MPEP ? 2107.

When a compound or composition claim is limited by a 
particular use, enablement of that claim should be evalu-
ated based on that limitation. See In re Vaeck, 947 F.2d 488, 
495, 20 USPQ2d 1438, 1444 (Fed. Cir. 1991) (claiming a 
chimeric gene capable of being expressed in any cyanobac-
terium and thus defining the claimed gene by its use).

In contrast, when a compound or composition claim is 
not limited by a recited use, any enabled use that would 
reasonably correlate with the entire scope of that claim is 
sufficient to preclude a rejection for nonenablement based 
on how to use. If multiple uses for claimed compounds or 
compositions are disclosed in the application, then an 
enablement rejection must include an explanation, suffi-
ciently supported by the evidence, why the specification 
fails to enable each disclosed use.  In other words, if any 
use is enabled when multiple uses are disclosed, the appli-
cation is enabling for the claimed invention.

2164.02	Working Example

Compliance with the enablement requirement of 
35 U.S.C. 112, first paragraph, does not turn on whether an 
example is disclosed. An example may be "working" or 
"prophetic." A working example is based on work actually 
performed. A prophetic example describes an embodiment 
of the invention based on predicted results rather than work 
actually conducted or results actually achieved. 

An applicant need not have actually reduced the inven-
tion to practice prior to filing. In Gould v. Quigg, 822 F.2d 
1074, 1078, 3 USPQ 2d 1302, 1304 (Fed. Cir. 1987), as of 
Gould's filing date, no person had built a light amplifier or 
measured a population inversion in a gas discharge. The 
Court held that "The mere fact that something has not pre-
viously been done clearly is not, in itself, a sufficient basis 
for rejecting all applications purporting to disclose how to 
do it." 822 F.2d at 1078, 3 USPQ2d at 1304 (quoting In re 
Chilowsky, 229 F.2d 457, 461, 108 USPQ 321, 325 (CCPA 
1956)). 

The specification need not contain an example if the 
invention is otherwise disclosed in such manner that one 
skilled in the art will be able to practice it without an undue 
amount of experimentation. In re Borkowski, 422 F.2d 904, 
908, 164 USPQ 642, 645 (CCPA 1970). 

Lack of a working example, however, is a factor to be 
considered, especially in a case involving an unpredictable 
and undeveloped art. But because only an enabling disclo-
sure is required, applicant need not describe all actual 
embodiments. 

NONE OR ONE WORKING EXAMPLE

When considering the factors relating to a determination 
of non-enablement, if all the other factors point toward 
enablement, then the absence of working examples will not 
by itself render the invention non-enabled.  In other words, 
lack of working examples or lack of evidence that the 
claimed invention works as described should never be the 
sole reason for rejecting the claimed invention on the 
grounds of lack of enablement.  A single working example 
in the specification for a claimed invention is enough to 
preclude a rejection which states that nothing is enabled 
since at least that embodiment would be enabled. However, 
a rejection stating that enablement is limited to a particular 
scope may be appropriate.

The presence of only one working example should never 
be the sole reason for rejecting claims as being broader than 
the enabling disclosure, even though it is a factor to be con-
sidered along with all the other factors.  To make a valid 
rejection, one must evaluate all the facts and evidence and 
state why one would not expect to be able to extrapolate 
that one example across the entire scope of the claims.

CORRELATION: IN VITRO/IN VIVO

The issue of "correlation" is related to the issue of the 
presence or absence of working examples.  "Correlation" as 
used herein refers to the relationship between in vitro or in 
vivo animal model assays and a disclosed or a claimed 
method of use.  An in vitro or in vivo animal model exam-
ple in the specification, in effect, constitutes a "working 
example" if that example "correlates" with a disclosed or 
claimed method invention.  If there is no correlation, then 
the examples do not constitute "working examples."  In this 
regard, the issue of "correlation" is also dependent on the 
state of the prior art.  In other words, if the art is such that a 
particular model is recognized as correlating to a specific 
condition, then it should be accepted as correlating unless 
the examiner has evidence that the model does not corre-
late.  Even with such evidence, the examiner must weigh 
the evidence for and against correlation and decide whether 
one skilled in the art would accept the model as reasonably 
correlating to the condition. In re Brana, 51 F.3d 1560, 
1566, 34 USPQ2d 1436, 1441 (Fed. Cir. 1995) (reversing 
the PTO decision based on finding that in vitro data did not 
support in vivo applications).

Since the initial burden is on the examiner to give rea-
sons for the lack of enablement, the examiner must also 
give reasons for a conclusion of lack of correlation for an in 
vitro or in vivo animal model example. A rigorous or an 
invariable exact correlation is not required, as stated in 
Cross v. Iizuka, 753 F.2d 1040, 1050, 224 USPQ 739, 747  
(Fed. Cir. 1985):

[B]ased upon the relevant evidence as a whole, there is a reason-
able correlation between the disclosed in vitro utility and an in 
vivo activity, and therefore a rigorous correlation is not necessary 
where the disclosure of pharmacological activity is reasonable 
based upon the probative evidence. (Citations omitted.)

WORKING EXAMPLES AND A CLAIMED GENUS

For a claimed genus, representative examples together 
with a statement applicable to the genus as a whole will 
ordinarily be sufficient if one skilled in the art (in view of 
level of skill, state of the art and the information in the 
specification) would expect the claimed genus could be 
used in that manner without undue experimentation. Proof 
of enablement will be required for other members of the 
claimed genus only where adequate reasons are advanced 
by the examiner to establish that a person skilled in the art 
could not use the genus as a whole without undue experi-
mentation. 

2164.03	Relationship of Predictability 
of the Art and the Enablement 
Requirement

 The amount of guidance or direction needed to enable 
the invention is inversely related to the amount of knowl-
edge in the state of the art as well as the predictability in the 
art. In re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 
(CCPA 1970). The "amount of guidance or direction" 
refers to that information in the application, as originally 
filed, that teaches exactly how to make or use the invention.  
The more that is known in the prior art about the nature of 
the invention, how to make, and how to use the invention, 
and the more predictable the art is, the less information 
needs to be explicitly stated in the specification. In contrast, 
if little is known in the prior art about the nature of the 
invention and the art is unpredictable, the specification 
would need more detail as to how to make and use the 
invention in order to be enabling.

The "predictability or lack thereof" in the art refers to the 
ability of one skilled in the art to extrapolate the disclosed 
or known results to the claimed invention.  If one skilled in 
the art can readily anticipate the effect of a change within 
the subject matter to which the claimed invention pertains, 
then there is predictability in the art.  On the other hand, if 
one skilled in the art cannot readily anticipate the effect of a 
change within the subject matter to which that claimed 
invention pertains, then there is lack of predictability in the 
art. Accordingly, what is known in the art provides evi-
dence as to the question of predictability.  In particular, the 
court in In re Marzocchi, 439 F.2d 220, 223-24, 169 USPQ 
367, 369-70 (CCPA 1971), stated: 

[I]n the field of chemistry generally, there may be times when 
the well-known unpredictability of chemical reactions will alone 
be enough to create a reasonable doubt as to the accuracy of a 
particular broad statement put forward as enabling support for a 
claim. This will especially be the case where the statement is, on 
its face, contrary to generally accepted scientific principles.  
Most often, additional factors, such as the teachings in pertinent 
references, will be available to substantiate any doubts that the 
asserted scope of objective enablement is in fact commensurate 
with the scope of protection sought and to support any demands 
based thereon for proof.  [Footnote omitted.]

The scope of the required enablement varies inversely 
with the degree of predictability involved, but even in 
unpredictable arts, a disclosure of every operable species is 
not required. A single embodiment may provide broad 
enablement in cases involving predictable factors, such as 
mechanical or electrical elements. In re Vickers, 141 F.2d 
522, 526-27, 61 USPQ 122, 127 (CCPA 1944); In re Cook, 
439 F.2d 730, 734, 169 USPQ 298, 301 (CCPA 1971). 
However, in applications directed to inventions in arts 
where the results are unpredictable, the disclosure of a sin-
gle species usually does not provide an adequate basis to 
support generic claims. In re Soll, 97 F.2d 623, 624, 38 
USPQ 189, 191 (CCPA 1938). In cases involving unpre-
dictable factors, such as most chemical reactions and physi-
ological activity, more may be required. In re Fisher, 427 
F.2d 833, 839, 166 USPQ 18, 24 (CCPA 1970) (contrasting 
mechanical and electrical elements with chemical reactions 
and physiological activity). See also In re Wright, 999 F.2d 
1557, 1562, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993); In re 
Vaeck, 947 F.2d 488, 496, 20 USPQ2d 1438, 1445 (Fed. 
Cir. 1991). This is because it is not obvious from the disclo-
sure of one species, what other species will work. 

2164.04	Burden on the Examiner Under the 
Enablement Requirement

Before any analysis of enablement can occur, it is neces-
sary for the examiner to construe the claims. For terms that 
are not well-known in the art, or for terms that could have 
more than one meaning, it is necessary that the examiner 
select the definition that he/she intends to use when exam-
ining the application, based on his/her understanding of 
what applicant intends it to mean, and explicitly set forth 
the meaning of the term and the scope of the claim when 
writing an Office action.  See Genentech v. Wellcome Foun-
dation, 29 F.3d 1555, 1563-64, 31 USPQ2d 1161, 1167-68 
(Fed. Cir. 1994).

In order to make a rejection, the examiner has the initial 
burden to establish a reasonable basis to question the 
enablement provided for the claimed invention. In re 
Wright, 999 F.2d 1557, 1562, 27 USPQ2d 1510, 1513 (Fed. 
Cir. 1993) (examiner must provide a reasonable explana-
tion as to why the scope of protection provided by a claim 
is not adequately enabled by the disclosure). A specifica-
tion disclosure which contains a teaching of the manner and 
process of making and using an invention in terms which 
correspond in scope to those used in describing and defin-
ing the subject matter sought to be patented must be taken 
as being in compliance with the enablement requirement  of  
35 U.S.C. 112, first paragraph, unless there is a reason to 
doubt the objective truth of the statements contained 
therein which must be relied on for enabling support. 
Assuming that sufficient reason for such doubt exists, a 
rejection for failure to teach how to make and/or use will be 
proper on that basis.  In re Marzocchi, 439 F.2d 220, 224, 
169 USPQ  367, 370 (CCPA 1971).  As stated by the court, 
"it is incumbent upon the Patent Office, whenever a rejec-
tion on this basis is made, to explain why it doubts the truth 
or accuracy of any statement in a supporting disclosure and 
to back up assertions of its own with acceptable evidence or 
reasoning which is inconsistent with the contested state-
ment. Otherwise, there would be no need for the applicant 
to go to the trouble and expense of supporting his presump-
tively accurate disclosure." 439 F.2d at 224, 169 USPQ at 
370.

According to In re Bowen, 492 F.2d 859, 862-63, 181 
USPQ 48, 51 (CCPA 1974), the minimal requirement is for 
the examiner to give reasons for the uncertainty of the 
enablement. This standard is applicable even when there is 
no evidence in the record of operability without undue 
experimentation beyond the disclosed embodiments. See 
also In re Brana, 51 F.3d 1560, 1566, 34 USPQ2d 1436 
,1441 (Fed. Cir. 1995) (citing In re Bundy, 642 F.2d 430, 
433, 209 USPQ 48, 51 (CCPA 1981)) (discussed in  MPEP 
? 2164.07 regarding the relationship of the enablement 
requirement to the utility requirement of  35 U.S.C. 101). 

While the analysis and conclusion of a lack of enable-
ment are based on the factors discussed in MPEP 
? 2164.01(a) and the evidence as a whole, it is not neces-
sary to discuss each factor in the written enablement rejec-
tion. The language should focus on those factors, reasons, 
and evidence that lead the examiner to conclude that the 
specification fails to teach how to make and use the 
claimed invention without undue experimentation, or that 
the scope of any enablement provided to one skilled in the 
art is not commensurate with the scope of protection sought 
by the claims. This can be done by making specific find-
ings of fact, supported by the evidence, and then drawing 
conclusions based on these findings of fact. For example, 
doubt may arise about enablement because information is 
missing about one or more essential parts or relationships 
between parts which one skilled in the art could not 
develop without undue experimentation.  In such a case, the 
examiner should specifically identify what information is 
missing and why one skilled in the art could not supply the 
information without undue experimentation. See MPEP 
? 2164.06(a). References should be supplied if possible to 
support a prima facie case of lack of enablement, but are 
not always required. In re Marzocchi, 439 F.2d 220, 224, 
169 USPQ 367, 370 (CCPA 1971).  However, specific tech-
nical reasons are always required.

In accordance with the principles of compact prosecu-
tion, if an enablement rejection is appropriate, the first 
Office action on the merits should present the best case 
with all the relevant reasons, issues, and evidence so that all 
such rejections can be withdrawn if applicant provides 
appropriate convincing arguments and/or evidence in rebut-
tal.  Providing the best case in the first Office action will 
also allow the second Office action to be made final should 
applicant fail to provide appropriate convincing arguments 
and/or evidence. Citing new references and/or expanding 
arguments in a second Office action could prevent that 
Office action from being made final.  The principles of 
compact prosecution also dictate that if an enablement 
rejection is appropriate and the examiner recognizes limita-
tions that would render the claims enabled, the examiner 
should note such limitations to applicant as early in the 
prosecution as possible. 

In other words, the examiner should always look for 
enabled, allowable subject matter and communicate to 
applicant what that subject matter is at the earliest point 
possible in the prosecution of the application.

2164.05	Determination of Enablement 
Based on Evidence As a Whole

Once the examiner has weighed all the evidence and 
established a reasonable basis to question the enablement 
provided for the claimed invention, the burden falls on 
applicant to present persuasive arguments, supported by 
suitable proofs where necessary, that one skilled in the art 
would be able to make and use the claimed invention using 
the application as a guide. In re Brandstadter, 484 F.2d 
1395, 1406-07, 179 USPQ 286, 294 (CCPA 1973).  The 
evidence provided by applicant need not be conclusive but 
merely convincing to one skilled in the art.  

Applicant may submit factual affidavits under 37 CFR 
1.132 or cite references to show what one skilled in the art 
knew at the time of filing the application. A declaration or 
affidavit is, itself, evidence that must be considered. The 
weight to give a declaration or affidavit will depend upon 
the amount of factual evidence the declaration or affidavit 
contains to support the conclusion of enablement. In re 
Buchner, 929 F.2d 660, 661, 18 USPQ2d 1331, 1332 (Fed. 
Cir. 1991) ("expert's opinion on the ultimate legal conclu-
sion must be supported by something more than a conclu-
sory statement"); cf. In re Alton, 76 F.3d 1168, 1174, 37 
USPQ2d 1578, 1583 (Fed. Cir. 1996) (declarations relating 
to the written description requirement should have been 
considered).

Applicant should be encouraged to provide any evidence 
to demonstrate that the disclosure enables the claimed 
invention.  In chemical and biotechnical applications, evi-
dence actually submitted to the FDA to obtain approval for 
clinical trials may be submitted. However, considerations 
made by the FDA for approving clinical trials are different 
from those made by the PTO in determining whether a 
claim is enabled.  See Scott v. Finney, 34 F.3d 1058, 1063, 
32 USPQ2d 1115, 1120 (Fed. Cir. 1994) ("Testing for full 
safety and effectiveness of a prosthetic device is  more 
properly left to the [FDA].").  Once that evidence is sub-
mitted, it must be weighed with all other evidence accord-
ing to the standards set forth above so as to reach a 
determination as to whether the disclosure enables the 
claimed invention.  

To overcome a prima facie case of lack of enablement, 
applicant must demonstrate by argument and/or evidence 
that the disclosure, as filed, would have enabled the 
claimed invention for one skilled in the art at the time of fil-
ing.  This does not preclude applicant from providing a 
declaration after the filing date which demonstrates that the 
claimed invention works. However, the examiner should 
carefully compare the steps, materials, and conditions used 
in the experiments of the declaration with those disclosed 
in the application to make sure that they are commensurate 
in scope; i.e., that the experiments used the guidance in the 
specification as filed and what was well known to one of 
skill in the art.  Such a showing also must be commensurate 
with the scope of the claimed invention, i.e., must bear a 
reasonable correlation to the scope of the claimed inven-
tion.  

The examiner must then weigh all the evidence before 
him or her, including the specification and any new evi-
dence supplied by applicant with the evidence and/or sound 
scientific reasoning previously presented in the rejection 
and decide whether the claimed invention is enabled. The 
examiner should never make the determination based on 
personal opinion. The determination should always be 
based on the weight of all the evidence.

2164.05(a)	Specification Must Be Enabling as 
of the Filing Date

Whether the specification would have been enabling as 
of the filing date involves consideration of the nature of the 
invention, the state of the prior art, and the level of skill in 
the art.  The initial inquiry is into the nature of the inven-
tion, i.e., the subject matter to which the claimed invention 
pertains. The nature of the invention becomes the backdrop 
to determine the state of the art and the level of skill pos-
sessed by one skilled in the art. 

The state of the prior art is what one skilled in the art 
would have known, at the time the application was filed, 
about the subject matter to which the claimed invention 
pertains.  The relative skill of those in the art refers to the 
skill of those in the art in relation to the subject matter to 
which the claimed invention pertains at the time the appli-
cation was filed.  See MPEP ? 2164.05(b).

The state of the prior art provides evidence for the 
degree of predictability in the art and is related to the 
amount of direction or guidance needed in the specification 
as filed to meet the enablement requirement. The state of 
the prior art is also related to the need for working exam-
ples in the specification. 

The state of the art for a given technology is not static in 
time.  It is entirely possible that a disclosure filed on Janu-
ary 2, 1990, would not have been enabled.  However, if the 
same disclosure had been filed on January 2, 1996, it might 
have enabled the claims. Therefore, the state of the prior art 
must be evaluated for each application based on its filing 
date.

35 U.S.C. 112 requires the specification to be enabling 
only to a person "skilled in the art to which it pertains, or 
with which it is most nearly connected."  In general, the 
pertinent art should be defined in terms of the problem to 
be solved rather than in terms of the technology area, indus-
try, trade, etc. for which the invention is used.  

The specification need not disclose what is well-known 
to those skilled in the art and preferably omits that which is 
well-known to those skilled and already available to the 
public. In re Buchner,  929 F.2d 660, 661, 18 USPQ2d 
1331, 1332 (Fed. Cir. 1991); Hybritech,  Inc. v. Monoclonal 
Antibodies, Inc., 802 F.2d 1367, 1384, 231 USPQ 81, 94 
(Fed. Cir. 1986), cert. denied, 480 U.S. 947 (1987); and 
Lindemann Maschinenfabrik GMBH v. American Hoist & 
Derrick Co., 730 F.2d  1452, 1463, 221 USPQ 481, 489 
(Fed. Cir. 1984).  

The state of the art existing at the filing date of the appli-
cation is used to determine whether a particular disclosure 
is enabling as of the filing date. Publications dated after the 
filing date providing information publicly first disclosed 
after the filing date generally cannot be used to show what 
was known at the time of filing.  In re Gunn, 537 F.2d 1123, 
1128, 190 USPQ 402,405-06 (CCPA 1976); In re Budnick, 
537 F.2d 535, 538, 190 USPQ 422, 424 (CCPA 1976) (In 
general, if an applicant seeks to use a patent to prove the 
state of the art for the purpose of the enablement require-
ment, the patent must have an issue date earlier than the 
effective filing date of the application.). While a later dated 
publication cannot supplement an insufficient disclosure in 
a prior dated application to make it enabling, applicant can 
offer the testimony of an expert based on the publication as 
evidence of the level of skill in the art at the time the appli-
cation was filed.   Gould v. Quigg, 822 F.2d 1074, 1077, 3 
USPQ2d 1302, 1304 (Fed. Cir. 1987). 

In general, the examiner should not use post-filing date 
references to demonstrate that the patent is non-enabling.  
Exceptions to this rule could occur if a later-dated reference 
provides evidence of what one skilled in the art would have 
known on or before the effective filing date of the patent 
application.  In re Hogan, 559 F.2d 595, 605, 194 USPQ 
527, 537 (CCPA 1977).  If individuals of skill in the art 
state that a particular invention is not possible years after 
the filing date, that would be evidence that the disclosed 
invention was not possible at the time of filing and should 
be considered.  In In re Wright, 999 F.2d 1557, 1562, 27 
USPQ2d 1510, 1513-14 (Fed. Cir. 1993) an article pub-
lished 5 years after the filing date of the application ade-
quately supported the examiner's position that the 
physiological activity of certain viruses was sufficiently 
unpredictable so that a person skilled in the art would not 
have believed that the success with one virus and one ani-
mal could be extrapolated successfully to all viruses with 
all living organisms. Claims not directed to the specific 
virus and the specific animal were held nonenabled.

2164.05(b)	Specification Must Be Enabling to 
Persons Skilled in the Art

The relative skill of those in the art refers to the skill of 
those in the art in relation to the subject matter to which the 
claimed invention pertains at the time the application was 
filed. Where different arts are involved in the invention, the 
specification is enabling if it enables persons skilled in each 
art to carry out the aspect of the invention applicable to 
their specialty. In re Naquin, 398 F.2d 863, 866, 158 USPQ 
317, 319 (CCPA 1968).

When an invention, in its different aspects, involves dis-
tinct arts, the specification is enabling if it enables those 
skilled in each art, to carry out the aspect proper to their 
specialty. "If two distinct technologies are relevant to an 
invention, then the disclosure will be adequate if a person 
of ordinary skill in each of the two technologies could prac-
tice the invention from the disclosures."   Technicon Instru-
ments Corp. v. Alpkem Corp., 664 F. Supp. 1558, 1578, 2 
USPQ2d 1729, 1742 (D. Ore. 1986), aff'd in part, vacated 
in part, rev'd in part, 837 F. 2d 1097 (Fed. Cir. 1987) 
(unpublished opinion), appeal after remand, 866 F. 2d 417, 
9 USPQ 2d 1540 (Fed. Cir. 1989). In Ex parte Zechnall, 
194 USPQ 461 (Bd. App. 1973), the Board stated "appel-
lants' disclosure must be held sufficient if it would enable a 
person skilled in the electronic computer art, in cooperation 
with a person skilled in the fuel injection art, to make and 
use appellants' invention."  194 USPQ at 461.

2164.06	Quantity of Experimentation

The quantity of experimentation needed to be performed 
by one skilled in the art is only one factor involved in deter-
mining whether "undue experimentation" is required to 
make and use the invention.  "[A]n extended period of 
experimentation may not be undue if the skilled artisan is 
given sufficient direction or guidance."  In re Colianni, 561 
F.2d 220, 224, 195 USPQ 150, 153 (CCPA 1977).  " `The 
test is not merely quantitative, since a considerable amount 
of experimentation is permissible, if it is merely routine, or 
if the specification in question provides a reasonable 
amount of guidance with respect to the direction in which 
the experimentation should proceed.' " In re Wands, 858 
F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988) (cit-
ing In re Angstadt, 537 F.2d 489, 502-04, 190 USPQ 214, 
217-19 (CCPA 1976)).  Time and expense are merely fac-
tors in this consideration and are not the controlling factors. 
United States v. Telectronics Inc., 857 F.2d 778, 785, 8 
USPQ2d 1217, 1223 (Fed. Cir. 1988), cert. denied, 490 
U.S. 1046 (1989).

In the chemical arts, the guidance and ease in carrying 
out an assay to achieve the claimed objectives may be an 
issue to be considered in determining the quantity of exper-
imentation needed. For example, if a very difficult and time 
consuming assay is needed to identify a compound within 
the scope of a claim, then this great quantity of experimen-
tation should be considered in the overall analysis. Time 
and difficulty of experiments are not determinative if they 
are merely routine. Quantity of examples is only one factor 
that must be considered before reaching the final conclu-
sion that undue experimentation would be required. In re 
Wands, 858 F.2d at 737, 8 USPQ2d at 1404. 

I.	EXAMPLE OF REASONABLE EXPERIMEN-
TATION

In United States v. Telectronics, Inc., 857  F.2d 778, 8 
USPQ2d 1217 (Fed. Cir. 1988), cert. denied, 490 U.S. 1046 
(1989), the court reversed the findings of the district court 
for lack of clear and convincing proof that undue experi-
mentation was needed. The court ruled that since one 
embodiment (stainless steel electrodes) and the method to 
determine dose/response was set forth in the specification, 
the specification was enabling. The question of time and 
expense of such studies, approximately $50,000 and 6-12 
months standing alone, failed to show undue experimenta-
tion.

II.	EXAMPLE OF UNREASONABLE EXPERI-
MENTATION

In In re Ghiron, 442 F.2d 985, 991-92, 169 USPQ 723, 
727-28 (CCPA 1971), functional "block diagrams" were 
insufficient to enable a person skilled in the art to practice 
the claimed invention with only a reasonable degree of 
experimentation because the claimed invention required a 
"modification to prior art overlap computers," and because 
"many of the components which appellants illustrate as 
rectangles in their drawing necessarily are themselves com-
plex assemblages . . . .  It is common knowledge that many 
months or years elapse from the announcement of a new 
computer by a manufacturer before the first prototype is 
available.  This does not bespeak of a routine operation but 
of extensive experimentation and development work . . . ." 

2164.06(a)	Examples of Enablement Issues-
Missing Information

It is common that doubt arises about enablement because 
information is missing about one or more essential parts or 
relationships between parts which one skilled in the art 
could not develop without undue experimentation. In such 
a case, the examiner should specifically identify what infor-
mation is missing and why the missing information is 
needed to provide enablement.

I.	ELECTRICAL AND MECHANICAL DEVICES 
OR PROCESSES

For example, a disclosure of an electrical circuit appara-
tus, depicted in the drawings by block diagrams with func-
tional labels, was held to be nonenabling in In re Gunn, 537 
F.2d 1123, 1129, 190 USPQ 402, 406 (CCPA 1976). There 
was no indication in the specification as to whether the 
parts represented by boxes were "off the shelf" or must be 
specifically constructed or modified for applicant's system. 
Also there were no details in the specification of how the 
parts should be interconnected, timed and controlled so as 
to obtain the specific operations desired by the applicant. In 
In re Donohue, 550 F.2d 1269, 193 USPQ 136 (CCPA 
1977), the lack of enablement was caused by lack of infor-
mation in the specification about a single block labelled 
"LOGIC" in the drawings.

In re Ghiron, 442 F.2d 985, 169 USPQ 723 (CCPA 
1971), involved a method of facilitating transfers from one 
subset of program instructions to another which required 
modification of prior art "overlap mode" computers. The 
Board rejected the claims on the basis, inter alia, that the 
disclosure was insufficient to satisfy the requirements of  
35 U.S.C. 112, first paragraph and was affirmed. The Board 
focused on the fact that the drawings were "block diagrams, 
i.e., a group of rectangles representing the elements of the 
system, functionally labelled and interconnected by lines." 
442 F.2d at 991, 169 USPQ at 727. The specification did 
not particularly identify each of the elements represented 
by the blocks or the relationship therebetween, nor did it 
specify particular apparatus intended to carry out each 
function. The Board further questioned whether the selec-
tion and assembly of the required components could be car-
ried out routinely by persons of ordinary skill in the art.

An adequate disclosure of a device may require details 
of how complex components are constructed and perform 
the desired function. The claim before the court in In re 
Scarbrough, 500 F.2d 560, 182 USPQ 298 (CCPA 1974) 
was directed to a system which comprised several compo-
nent parts (e.g., computer, timing and control mechanism, 
A/D converter, etc.) only by generic name and overall ulti-
mate function. The court concluded that there was not an 
enabling disclosure because the specification did not 
describe how "complex elements known to perform 
broadly recited functions in different systems  would be 
adaptable for use in Appellant's particular system with only 
a reasonable amount of experimentation" and that "an 
unreasonable amount of work would be required to arrive 
at the detailed relationships appellant says that he has 
solved." 500 F.2d at 566, 182 USPQ at 302.

II.	MICROORGANISMS

Patent applications involving living biological products, 
such as microorganisms, as critical elements in the process 
of making the invention, present a unique question with 
regard to availability. The issue was raised in a case involv-
ing claims drawn to a fermentative method of producing 
two novel antibiotics using a specific microorganism and 
claims to the novel antibiotics so produced. In re Argoude-
lis, 434 F.2d 1390, 168 USPQ 99 (CCPA 1970). As stated 
by the court, "a unique aspect of using microorganisms as 
starting materials is that a sufficient description of how to 
obtain the microorganism from nature cannot be given." 
434 F.2d at 1392, 168 USPQ at 102. It was determined by 
the court that availability of the biological product via a 
public depository provided an acceptable means of meeting 
the written description and the enablement requirements of  
35 U.S.C. 112, first paragraph.

To satisfy the enablement requirement a deposit must be 
made "prior to issue" but need not be made prior to filing 
the application. In re Lundak, 773 F.2d 1216, 1223, 227 
USPQ 90, 95 (Fed. Cir. 1985).

The availability requirement of enablement must also be 
considered in light of the scope or breadth of the  claim lim-
itations. The Board of Appeals considered this issue in an 
application which claimed a fermentative method using 
microorganisms belonging to a species. Applicants had 
identified three novel individual strains of microorganisms 
that were related in such a way as to establish a new species 
of microorganism, a species being a broader classification 
than a strain. The three specific strains had been appropri-
ately deposited. The issue focused on whether the specifi-
cation enabled one skilled in the art to make any member of 
the species other than the three strains which had been 
deposited. The Board concluded that the verbal description 
of the species was inadequate to allow a skilled artisan to 
make any and all members of the claimed species. Ex parte 
Jackson, 217 USPQ 804, 806 (Bd. App. 1982). 

See  MPEP ? 2402 -  ? 2411.03 for a detailed discussion 
of the deposit rules. See MPEP ? 2411.01 for rejections 
under  35 U.S.C. 112 based on deposit issues.

III.	DRUG CASES

See  MPEP ? 2107 - ? 2107.02 for a discussion of the 
utility requirement under 35 U.S.C. 112, first paragraph, in 
drug cases.

2164.06(b)	Examples of Enablement Issues - 
Chemical Cases [R-1]

The following summaries should not be relied on to sup-
port a case of lack of enablement without carefully reading 
the case.

SEVERAL DECISIONS RULING THAT THE DIS-
CLOSURE WAS NONENABLING 

>

(A)	In Enzo Biochem, Inc. v. Calgene, Inc., 188 F.3d 
1362, 52 USPQ2d 1129 (Fed. Cir. 1999), the court held that 
claims in two patents directed to genetic antisense technol-
ogy (which aims to control gene expression in a particular 
organism), were invalid because the breadth of enablement 
was not commensurate in scope with the claims. Both spec-
ifications disclosed applying antisense technology in regu-
lating three genes in E. coli. Despite the limited disclosures, 
the specifications asserted that the "[t]he practices of this 
invention are generally applicable with respect to any 
organism containing genetic material which is capable of 
being expressed ? such as bacteria, yeast, and other cellu-
lar organisms." The claims of the patents encompassed 
application of antisense methodology in a broad range of 
organisms. Ultimately, the court relied on the fact that (1) 
the amount of direction presented and the number of work-
ing examples provided in the specification were very nar-
row compared to the wide breadth of the claims at issue, (2) 
antisense gene technology was highly unpredictable, and 
(3) the amount of experimentation required to adapt the 
practice of creating antisense DNA from E. coli to other 
types of cells was quite high, especially in light of the 
record, which included notable examples of the inventor's 
own failures to control the expression of other genes in E. 
coli and other types of cells. Thus, the teachings set forth in 
the specification provided no more than a "plan" or "invita-
tion" for those of skill in the art to experiment using the 
technology in other types of cells. <

*>

(B)<

In In re Wright, 999 F.2d 1557, 27 USPQ2d 1510 (Fed. 
Cir. 1993), the 1983 application disclosed a vaccine against 
the RNA tumor virus known as Prague Avian Sarcoma 
Virus, a member of the Rous Associated Virus family.  
Using functional language, Wright claimed a vaccine 
"comprising an immunologically effective amount" of a 
viral expression product. Id., at 1559, 27 USPQ2d at 1511.  
Rejected claims covered all RNA viruses as well as avian 
RNA viruses. The examiner provided a teaching that in 
1988, a vaccine for another retrovirus (i.e., AIDS) 
remained an intractable problem. This evidence, along with 
evidence that the RNA viruses were a diverse and compli-
cated genus, convinced the Federal Circuit that the inven-
tion was not enabled for either all retroviruses or even for 
avian retroviruses.

*>

(C)<

In In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 
(Fed. Cir. 1993), a 1985 application functionally claimed a 
method of producing protein in plant cells by expressing a 
foreign gene. The court stated: "[n]aturally, the specifica-
tion must teach those of skill in the art `how to make and 
use the invention as broadly as it is claimed.' " Id. at 1050, 
29 USPQ2d at 2013.  Although protein expression in dicot-
yledonous plant cells was enabled, the claims covered any 
plant cell.  The examiner provided evidence that even as 
late as 1987, use of the claimed method in monocot plant 
cells was not enabled. Id. at 1051, 29 USPQ2d at 2014.

*>

(D)<

In   In re Vaeck, 947 F.2d 488, 495, 20 USPQ2d 1438, 
1444 (Fed. Cir. 1991), the court found that several claims 
were not supported by an enabling disclosure "[t]aking into 
account the relatively incomplete understanding of the biol-
ogy of cyanobacteria as of appellants' filing date, as well as 
the limited disclosure by appellants of the particular cyano-
bacterial genera operative in the claimed invention...."  The 
claims at issue were not limited to any particular genus or 
species of cyanobacteria and the specification mentioned 
nine genera and the working examples employed one spe-
cies of cyanobacteria.

*>

(E)<

In   In re Colianni, 561 F.2d 220, 222-23, 195 USPQ 
150, 152 (CCPA 1977), the court affirmed a rejection under  
35 U.S.C. 112, first paragraph, because the specification, 
which was directed to a method of mending a fractured 
bone by applying "sufficient" ultrasonic energy to the bone, 
did not define a "sufficient" dosage or teach one of ordi-
nary skill how to select the appropriate intensity, frequency, 
or duration of the ultrasonic energy. 

SEVERAL DECISIONS RULING THAT THE DIS-
CLOSURE WAS ENABLING 

(A)	In PPG Ind. v. Guardian Ind., 75 F.3d 1558, 1564, 
37 USPQ2d 1618, 1623 (Fed. Cir. 1996), the court ruled 
that even though there was a software error in calculating 
the ultraviolet transmittance data for examples in the speci-
fication making it appear that the production of a cerium 
oxide-free glass that satisfied the transmittance limitation 
would be difficult, the specification indicated that such 
glass could be made.  The specification was found to indi-
cate how to minimize the cerium content while maintaining 
low  ultraviolet transmittance. 

(B)	In In re Wands, 858 F.2d 731, 8 USPQ2d 1400 
(Fed. Cir. 1988), the court reversed the rejection for lack of 
enablement under 35 U.S.C. 112, first paragraph, conclud-
ing that undue experimentation would not be required to 
practice the invention. The nature of monoclonal antibody 
technology is such that experiments first involve the entire 
attempt to make monoclonal hybridomas to determine 
which ones secrete antibody with the desired characteris-
tics. The court found that the specification provided consid-
erable direction and guidance on how to practice the 
claimed invention and presented working examples, that all 
of the methods needed to practice the invention were well 
known, and that there was a high level of skill in the art at 
the time the application was filed. Furthermore, the appli-
cant carried out the entire procedure for making a mono-
clonal antibody against HBsAg three times and each time 
was successful in producing at least one antibody which 
fell within the scope of the claims.

(C)	In In re Bundy, 642  F.2d 430, 434, 209 USPQ 48, 
51-52 (CCPA 1981), the court ruled that appellant's disclo-
sure was sufficient to enable one skilled in the art to use the 
claimed analogs of naturally occurring prostaglandins even 
though the specification lacked any examples of specific 
dosages, because the specification taught that the novel 
prostaglandins had certain  pharmacological properties and 
possessed activity similar to known E-type prostaglandins.

2164.07	Relationship of Enablement 
Requirement to Utility  
Requirement of 35 U.S.C. 101

The requirement of 35 U.S.C. 112, first paragraph as to 
how to use the invention is different from the utility 
requirement of 35 U.S.C. 101. The requirement of 
35 U.S.C. 101 is that some use be set forth for the inven-
tion, and that the use be provable and not against public 
policy. On the other hand, 35 U.S.C. 112, first paragraph 
requires an indication of how the use (required by section 
101) can be carried out, i.e., how the invention can be used. 

If an applicant has disclosed a specific utility for an 
invention and provided a credible basis supporting that spe-
cific utility, that fact alone does not provide a basis for con-
cluding that the claims comply with all the requirements of  
35 U.S.C. 112, first paragraph. For example, if an applicant 
has claimed a process of treating a certain disease condition 
with a certain compound and provided a credible basis for 
asserting that the compound is useful in that regard, but to 
actually practice the invention as claimed a person skilled 
in the relevant art would have to engage in an undue 
amount of experimentation, the claim may be defective 
under 35 U.S.C. 112, but not 35 U.S.C. 101. To avoid con-
fusion during examination, any rejection under 35 U.S.C. 
112, first paragraph, based on grounds other than "lack of 
utility" should be imposed separately from any rejection 
imposed due to "lack of utility" under 35 U.S.C. 101 and  
35 U.S.C. 112, first paragraph.

I.	WHEN UTILITY REQUIREMENT IS NOT 
SATISFIED

A.	Not Useful or Operative

If a claim fails to meet the utility requirement of  35 
U.S.C. 101 because it is shown to be nonuseful or inopera-
tive, then it necessarily fails to meet the how-to-use aspect 
of the enablement requirement of 35 U.S.C. 112, first para-
graph. As noted in In re Fouche, 439 F.2d 1237, 169 USPQ 
429 (CCPA 1971), if "compositions are in fact useless, 
appellant's specification cannot have taught how to use 
them." 439 F.2d at 1243, 169 USPQ at 434. The examiner 
should make both rejections (i.e., a rejection under 
35 U.S.C. 112, first paragraph and a rejection under 
35 U.S.C. 101) where the subject matter of a claim has 
been shown to be nonuseful or inoperative.

The 35 U.S.C. 112, first paragraph, rejection should indi-
cate that because the invention as claimed does not have 
utility, a person skilled in the art would not be able to use 
the invention as claimed, and as such, the claim is defective 
under 35 U.S.C. 112, first paragraph. A 35 U.S.C. 112, first 
paragraph, rejection should not be imposed or maintained 
unless an appropriate basis exists for imposing a rejection 
under 35 U.S.C. 101. In other words, Office personnel 
should not impose a 35 U.S.C. 112, first paragraph, rejec-
tion grounded on a "lack of utility" basis unless a 35 U.S.C. 
101 rejection is proper. In particular, the factual showing 
needed to impose a rejection under 35 U.S.C. 101 must be 
provided if a 35 U.S.C. 112, first paragraph, rejection is to 
be imposed on "lack of utility" grounds. See MPEP 
? 706.03(a)(1) and ? 2107 - ? 2107.02 for a more detailed 
discussion of the utility requirements of 35 U.S.C. 101 and 
112, first paragraph.

B.	Burden on the Examiner

When the examiner concludes that an application is 
describing an invention that  is nonuseful, inoperative, or 
contradicts known scientific principles, the burden is on the 
examiner to provide a reasonable basis to support this con-
clusion. Rejections based on 35 U.S.C. 112, first paragraph 
and  35 U.S.C. 101 should be made. 

Examiner Has Initial Burden To Show That One of 
Ordinary Skill in the Art Would Reasonably Doubt the 
Asserted Utility

The examiner has the initial burden of challenging an 
asserted utility. Only after the examiner has provided evi-
dence showing that one of ordinary skill in the art would 
reasonably doubt the asserted utility does the burden shift 
to the applicant to provide rebuttal evidence sufficient to 
convince one of ordinary skill in the art of the invention's 
asserted utility. In re Brana, 51 F.3d 1560, 1566, 34 
USPQ2d 1436, 1441 (Fed. Cir. 1995) (citing In re Bundy, 
642 F.2d 430, 433, 209 USPQ 48, 51 (CCPA 1981)).

C.	Rebuttal by Applicant

If a rejection under 35 U.S.C. 101 has been properly 
imposed, along with a corresponding rejection under 
35 U.S.C. 112, first paragraph, the burden shifts to the 
applicant to rebut the prima facie showing. In re Oetiker, 
977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 
1992).  There is no predetermined amount or character of 
evidence that must be provided by an applicant to support 
an asserted utility.  Rather, the character and amount of evi-
dence needed to support an asserted utility will vary 
depending on what is claimed (Ex parte Ferguson, 117 
USPQ 229, 231 (Bd. App. 1957)), and whether the asserted 
utility appears to contravene established scientific princi-
ples and beliefs. In re Gazave, 379 F.2d 973, 978, 154 
USPQ 92, 96 (CCPA 1967  ); In re Chilowsky, 229 F.2d 
457, 462, 108 USPQ 321, 325 (CCPA 1956). Furthermore, 
the applicant does not have to provide evidence sufficient 
to establish that an asserted utility is true "beyond a reason-
able doubt." In re Irons, 340 F.2d 974, 978, 144 USPQ 351, 
354 (CCPA 1965). Instead, evidence will be sufficient if, 
considered as a whole, it leads a person of ordinary skill in 
the art to conclude that the asserted utility is more likely 
than not true.  See MPEP ? 2107.01 for a more detailed dis-
cussion of consideration of a reply to a prima facie rejec-
tion for lack of utility and evaluation of evidence related to 
utility. 

II.	WHEN UTILITY REQUIREMENT IS SATIS-
FIED

In some instances, the use will be provided, but the 
skilled artisan will not know how to effect that use. In such 
a case, no rejection will be made under 35 U.S.C. 101, but a 
rejection will be made under 35 U.S.C. 112, first paragraph. 
As pointed out in Mowry v. Whitney, 81 U.S. (14 Wall.) 620 
(1871), an invention may in fact have great utility, i.e., may 
be "a highly useful invention," but the specification may 
still fail to "enable any person skilled in the art or science" 
to use the invention, 81 U.S. (14 Wall.) at 644. 

2164.08	Enablement Commensurate in  
Scope With the Claims

All questions of enablement are evaluated against the 
claimed subject matter.  The focus of the examination 
inquiry is whether everything within the scope of the claim 
is enabled.  Accordingly, the first analytical step requires 
that the examiner determine exactly what subject matter is 
encompassed by the claims. The examiner should deter-
mine what each claim recites and what the subject matter is 
when the claim is considered as a whole, not when its parts 
are analyzed individually.  No claim should be overlooked. 
With  respect to dependent claims, 35 U.S.C. 112,  fourth 
paragraph, should be followed.  This paragraph states that 
"a claim in a dependent form shall be construed to incorpo-
rate by reference all the limitations of the claim to which it 
refers" and requires the dependent claim to further limit the 
subject matter claimed. 

The Federal Circuit has repeatedly held that "the specifi-
cation must teach those skilled in the art how to make and 
use the full scope of the claimed invention without `undue 
experimentation'." In re Wright, 999 F.2d 1557, 1561, 27 
USPQ2d 1510, 1513 (Fed. Cir. 1993).  Nevertheless, not 
everything necessary to practice the invention need be dis-
closed.  In fact, what is well-known is best omitted. In re 
Buchner, 929 F.2d 660, 661, 18 USPQ2d 1331, 1332 (Fed. 
Cir. 1991).  All that is necessary is that one skilled in the art 
be able to practice the claimed invention, given the level of 
knowledge and skill in the art. Further the scope of enable-
ment must only bear a "reasonable correlation" to the scope 
of the claims.  See, e.g., In re Fisher,  427 F.2d 833, 839, 
166 USPQ 18, 24 (CCPA 1970).

As concerns the breadth of a claim relevant to enable-
ment, the only relevant concern should be whether the 
scope of enablement provided to one skilled in the art by 
the disclosure is commensurate with the scope of protection 
sought by the claims. In re Moore, 439 F.2d 1232, 1236, 
169 USPQ 236, 239 (CCPA 1971).

The determination of the propriety of a rejection  based 
upon the scope of a claim relative to the scope of the 
enablement involves two stages of inquiry. The first is to 
determine how broad the claim is with respect to the disclo-
sure. The entire claim must be considered. The second 
inquiry is to determine if one skilled in the art is enabled to 
make and use the entire scope of the claimed invention 
without undue experimentation.

How a teaching is set forth, by specific example or broad 
terminology, is not important. In re Marzocchi, 439 F.2d 
220, 223-24 169 USPQ 367, 370 (CCPA 1971). A rejection 
of a claim under 35 U.S.C. 112 as broader than the enabling 
disclosure is a first paragraph enablement rejection and not 
a second paragraph definiteness rejection. Claims are not 
rejected as broader than the enabling disclosure under 
35 U.S.C. 112 for noninclusion of limitations dealing with 
factors which must be presumed to be within the level of 
ordinary skill in the art; the claims need not recite such fac-
tors where one of ordinary skill in the art to whom the spec-
ification and claims are directed would consider them 
obvious.   In re Skrivan, 427 F.2d 801, 806, 166 USPQ 85, 
88 (CCPA 1970).  One does not look to the claims but to 
the specification to find out how to practice the claimed 
invention. W.L. Gore & Assoc., Inc. v. Garlock, Inc., 721 
F.2d 1540, 1558, 220 USPQ 303, 316-17 (Fed. Cir. 1983); 
In re Johnson, 558 F.2d 1008, 1017, 194 USPQ 187, 195 
(CCPA 1977).  In In re Goffe, 542 F.2d 564, 567, 191 
USPQ 429, 431 (CCPA 1976), the court stated:

[T]o provide effective incentives, claims must adequately protect 
inventors.  To demand that the first to disclose shall limit his 
claims to what he has found will work or to materials which meet 
the guidelines specified for "preferred" materials in a process 
such as the one herein involved would not serve the constitu-
tional purpose of promoting progress in the useful arts.

When analyzing the enabled scope of a claim, the teach-
ings of the specification must not be ignored because 
claims are to be given their broadest reasonable interpreta-
tion that is consistent with the specification.  "That claims 
are interpreted in light of the specification does not mean 
that everything in the specification must be read into the 
claims." Raytheon Co. v. Roper Corp., 724 F.2d 951, 957, 
220 USPQ 592, 597 (Fed. Cir. 1983), cert. denied, 469 U.S. 
835 (1984).     

The record must be clear so that the public will have 
notice as to the patentee's scope of protection when the 
patent issues.  If a reasonable interpretation of the claim is 
broader than the description in the specification, it is neces-
sary for the examiner to make sure the full scope of the 
claim is enabled. Limitations and examples in the specifica-
tion do not generally limit what is covered by the claims.

The breadth of the claims was a factor considered in 
Amgen v. Chugai Pharmaceutical Co., 927 F.2d 1200, 18 
USPQ2d 1016 (Fed. Cir.), cert. denied, 502 U.S. 856 
(1991).  In the Amgen case, the patent claims were directed 
to a purified DNA sequence encoding polypeptides which 
are analogs of erythropoietin (EPO). The Court stated that:

Amgen has not enabled preparation of DNA sequences sufficient 
to support its all-encompassing claims. . . . [D]espite extensive 
statements in the specification concerning all the analogs of  the 
EPO gene that can be made, there is little enabling disclosure of 
particular analogs and how to make them.  Details for preparing 
only a few EPO analog genes are disclosed. . . .  This disclosure 
might well justify a generic claim encompassing these and simi-
lar analogs, but it represents inadequate support for Amgen's 
desire to claim all EPO gene analogs.  There may be many other 
genetic sequences that code for EPO-type products.  Amgen has 
told how to make and use only a few of them and is therefore not 
entitled to claim all of them.

 927 F.2d at 1213-14, 18 USPQ2d at 1027.  However, 
when claims are directed to any purified and isolated DNA 
sequence encoding a specifically named protein where the 
protein has a specifically identified sequence, a rejection of 
the claims as broader than the enabling disclosure is gener-
ally not appropriate because one skilled in the art could 
readily determine any one of the claimed embodiments. 

See also In re Wright, 999 F.2d 1557, 1562, 27 USPQ2d 
1510, 1513 (Fed. Cir. 1993) (The evidence did not show 
that a skilled artisan would have been able to carry out the 
steps required to practice the full scope of claims which 
encompass "any and all live, non-pathogenic vaccines, and  
processes for making such vaccines, which elicit immuno-
protective activity in any animal toward any RNA virus." 
(original emphasis)); In re Goodman, 11 F.3d 1046, 1052, 
29 USPQ2d  2010, 2015 (Fed. Cir. 1993) (The specification 
did not enable the broad scope of the claims for producing 
mammalian peptides in plant cells because the specification 
contained only an example of producing gamma-interferon 
in a dicot species, and there was evidence that extensive 
experimentation would have been required for encoding 
mammalian peptide into a monocot plant at the time of fil-
ing); In re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 
(CCPA 1970) (Where applicant claimed a composition suit-
able for the treatment of arthritis having a potency of "at 
least" a particular value, the court held that the claim was 
not commensurate in scope with the enabling disclosure 
because the disclosure was not enabling for compositions 
having a slightly higher potency.  Simply because applicant 
was the first to achieve a composition beyond a particular 
threshold potency did not justify or support a claim that 
would dominate every composition that exceeded that 
threshold value.); In re Vaeck, 947 F.2d 488, 495, 20 
USPQ2d 1438, 1444 (Fed. Cir. 1991) (Given the  relatively 
incomplete understanding in the biotechnological field 
involved, and the lack of a reasonable correlation between 
the narrow disclosure in the specification and the broad 
scope of protection sought in the claims, a rejection under  
35 U.S.C. 112, first paragraph for lack of enablement was 
appropriate.).

If a rejection is made based on the view that the enable-
ment is not commensurate in scope with the claim, the 
examiner should identify the subject matter that is consid-
ered to be enabled.

2164.08(a)	Single Means Claim

A single means claim, i.e., where a means recitation does 
not appear in combination with another recited element of 
means, is subject to an undue breadth rejection under  35 
U.S.C. 112, first paragraph. In re Hyatt, 708 F.2d 712, 714-
715, 218 USPQ 195, 197 (Fed. Cir. 1983) (A single means 
claim which covered every conceivable means for achiev-
ing the stated purpose was held nonenabling for the scope 
of the claim because the specification disclosed at most 
only those means known to the inventor.). When claims 
depend on a recited property, a fact situation comparable to 
Hyatt is possible, where the claim covers every conceivable 
structure (means) for achieving the stated property (result) 
while the specification discloses at most only those known 
to the inventor. 

2164.08(b)	Inoperative Subject Matter

The presence of inoperative embodiments within  the 
scope of a claim does not necessarily render a claim nonen-
abled. The standard is whether a skilled person could deter-
mine which embodiments that were conceived, but not yet 
made, would be inoperative or operative with expenditure 
of no more effort than is normally required  in the art. Atlas 
Powder Co. v. E.I. du Pont de Nemours & Co., 750 F.2d 
1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984) (pro-
phetic examples do not make the disclosure nonenabling).

Although, typically, inoperative embodiments are 
excluded by language in a claim (e.g., preamble), the scope 
of the claim may still not be enabled where undue experi-
mentation is involved in determining those embodiments 
that are operable. A disclosure of a large number of opera-
ble embodiments and the identification of a single inopera-
tive embodiment did not render a claim broader than the 
enabled scope because undue experimentation was not 
involved in determining those embodiments that were oper-
able. In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 
214, 218 (CCPA 1976). However, claims reading on signif-
icant numbers of inoperative embodiments would render 
claims nonenabled when the specification does not clearly 
identify the operative embodiments and undue experimen-
tation is involved in determining those that are operative. 
Atlas Powder Co. v. E.I. duPont de Nemours & Co., 750 
F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984); In 
re Cook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 
1971).

2164.08(c)	Critical Feature Not Claimed  

A feature which is taught as critical in a specification 
and is not recited in the claims should result in a rejection 
of such claim under the enablement provision section of  35 
U.S.C. 112. See In re Mayhew, 527 F.2d 1229, 1233, 188 
USPQ 356, 358 (CCPA 1976). In determining whether an 
unclaimed feature is critical, the entire disclosure must be 
considered. Features which are merely preferred are not to 
be considered critical. In re Goffe, 542 F.2d 564, 567, 191 
USPQ 429, 431 (CCPA 1976). 

Limiting an applicant to the preferred materials in the 
absence of limiting prior art would not serve the constitu-
tional purpose of promoting the progress in the useful arts. 
Therefore, an enablement rejection based on the grounds 
that a disclosed critical limitation is missing from a claim 
should be made only when the language of the specification 
makes it clear that the limitation is critical for the invention 
to function as intended.  Broad language in the disclosure, 
including the abstract, omitting an allegedly critical feature, 
tends to rebut the argument of criticality.

2165	The Best Mode Requirement

A third requirement of the first paragraph of 35 U.S.C. 
112 is that:

The specification . . . shall set forth the best mode contemplated 
by the inventor of carrying out his invention.

The best mode requirement is a safeguard against the 
desire on the part of some people to obtain patent protec-
tion without making a full disclosure as required by the 
statute. The requirement does not permit inventors to dis-
close only what they know to be their second-best embodi-
ment, while retaining the best for themselves. In re Nelson, 
280 F.2d 172, 126 USPQ 242 (CCPA 1960).

The failure to disclose a better method will not invalidate 
a patent if the inventor, at the time of filing the application, 
did not know of the better method OR did not appreciate 
that it was the best method. All applicants are required to 
disclose for the claimed subject matter the best mode con-
templated by the inventor even though applicant may not 
have been the discoverer of that mode. Benger Labs. Ltd. v. 
R.K. Laros Co., 209 F. Supp. 639, 135 USPQ 11 (E.D. Pa. 
1962).

ACTIVE CONCEALMENT OR GROSSLY INEQUI-
TABLE CONDUCT IS NOT REQUIRED TO ESTAB-
LISH FAILURE TO DISCLOSE THE BEST MODE

Failure to disclose the best mode need not rise to the 
level of active concealment or grossly inequitable conduct 
in order to support a rejection or invalidate a patent. Where 
an inventor knows of a specific material that will make pos-
sible the successful reproduction of the effects claimed by 
the patent, but does not disclose it, speaking instead in 
terms of broad categories, the best mode requirement has 
not been satisfied. Union Carbide Corp. v. Borg-Warner, 
550 F.2d 555, 193 USPQ 1 (6th Cir. 1977).

If the failure to set forth the best mode in a patent disclo-
sure is the result of inequitable conduct (e.g., where the 
patent specification omitted crucial ingredients and dis-
closed a fictitious and inoperable slurry as Example 1), not 
only is that patent in danger of being held unenforceable, 
but other patents dealing with the same technology that are 
sought to be enforced in the same cause of action are sub-
ject to being held unenforceable. Consolidated Aluminum 
Corp. v. Foseco Inc., 910 F.2d 804, 15 USPQ2d 1481 (Fed. 
Cir. 1990).

2165.01	Considerations Relevant to Best 
Mode

I.	DETERMINE WHAT IS THE INVENTION

Determine what the invention is - the invention is 
defined in the claims. The specification need not set forth 
details not relating to the essence of the invention. In re 
Bosy, 360 F.2d 972, 149 USPQ 789 (CCPA 1966).

II.	SPECIFIC EXAMPLE IS NOT REQUIRED

There is no statutory requirement for the disclosure of a 
specific example - a patent specification is not intended 
nor required to be a production specification. In re Gay, 
309 F.2d 768, 135 USPQ 311 (CCPA 1962).

The absence of a specific working example is not neces-
sarily evidence that the best mode has not been disclosed, 
nor is the presence of one evidence that it has. Best mode 
may be represented by a preferred range of conditions or 
group of reactants. In re Honn, 364 F.2d 454, 150 USPQ 
652 (CCPA 1966).

III.	DESIGNATION AS BEST MODE IS NOT 
REQUIRED

There is no requirement in the statute that applicants 
point out which of their embodiments they consider to be 
their best; that the disclosure includes the best mode con-
templated by applicants is enough to satisfy the statute. 
Ernsthausen v. Nakayama, 1 USPQ2d 1539 (Bd. Pat. App. 
& Inter. 1985).

IV.	UPDATING BEST MODE IS NOT REQUIRED 

There is no requirement to update in the context of a for-
eign priority application under  35 U.S.C. 119, Standard Oil 
Co. v. Montedison, S.p.A., 494 F.Supp. 370, 206 USPQ 676 
(D.Del. 1980) (better catalyst developed between Italian 
priority and U.S. filing dates), and continuing applications 
claiming the benefit of an earlier filing date under 
35  U.S.C. 120, Transco Products, Inc. v. Performance 
Contracting Inc., 38 F.3d 551, 32 USPQ2d 1077 (Fed. Cir. 
1994) (continuation under  37 CFR 1.60); Sylgab Steel and 
Wire Corp. v. Imoco-Gateway Corp., 357 F.Supp. 657, 178 
USPQ 22 (N.D. Ill. 1973) (continuation); Johns-Manville 
Corp. v. Guardian Industries Corp., 586 F.Supp. 1034, 221 
USPQ 319 (E.D. Mich. 1983) (continuation and C-I-P). In 
the last cited case, the court stated that applicant would 
have been obliged to disclose an updated refinement if it 
were essential to the successful practice of the invention 
and it related to amendments to the C-I-P that were not 
present in the parent application. In Carter-Wallace, Inc. v. 
Riverton Labs., Inc., 433 F.2d 1034, 167 USPQ 656 (2d Cir. 
1970), the court assumed, but did not decide, that an appli-
cant must update the best mode when filing a C-I-P appli-
cation.

V.	DEFECT IN BEST MODE CANNOT BE 
CURED BY NEW MATTER

If the best mode contemplated by the inventor at the time 
of filing the application is not disclosed, such a defect can-
not be cured by submitting an amendment seeking to put 
into the specification something required to be there when 
the patent application was originally filed. In re Hay, 534 
F.2d 917, 189 USPQ 790 (CCPA 1976).

Any proposed amendment of this type (adding a specific 
mode of practicing the invention not described in the appli-
cation as filed) should be treated as new matter. New matter 
under 35 U.S.C. 132 and 251 should be objected to and 
coupled with a requirement to cancel the new matter.

2165.02	Best Mode Requirement Compared 
to Enablement Requirement

The best mode requirement is a separate and distinct 
requirement from the enablement requirement of the first 
paragraph of  35 U.S.C. 112. In re Newton, 414 F.2d 1400, 
163 USPQ 34 (CCPA 1969).

The best mode provision of 35 U.S.C. 112 is not directed 
to a situation where the application fails to set forth any 
mode - such failure is equivalent to nonenablement. In re 
Glass, 492 F.2d 1228, 181 USPQ 31 (CCPA 1974).

The enablement requirement looks to placing the 
subject matter of the claims generally in the possession of 
the public. If, however, the applicant develops specific 
instrumentalities or techniques which are recognized by the 
applicant at the time of filing as the best way of carrying 
out the invention, then the best mode requirement imposes 
an obligation to disclose that information to the public as 
well. Spectra-Physics, Inc. v. Coherent, Inc., 827 F.2d 
1524, 3 USPQ 2d 1737 (Fed. Cir.), cert. denied, 484 U.S. 
954 (1987).

2165.03	Requirements for Rejection for 
Lack of Best Mode

ASSUME BEST MODE IS DISCLOSED UNLESS 
THERE IS EVIDENCE TO THE CONTRARY

The examiner should assume that the best mode is dis-
closed in the application, unless evidence is presented that 
is inconsistent with that assumption. It is extremely rare 
that a best mode rejection properly would be made in ex 
parte prosecution. The information that is necessary to 
form the basis for a rejection based on the failure to set 
forth the best mode is rarely accessible to the examiner, but 
is generally uncovered during discovery procedures in 
interference, litigation, or other inter partes proceedings.

EXAMINER MUST DETERMINE WHETHER THE 
INVENTOR KNEW THAT ONE MODE WAS 
BETTER THAN ANOTHER, AND IF SO, WHETHER 
THE DISCLOSURE IS ADEQUATE TO ENABLE 
ONE OF ORDINARY SKILL IN THE ART TO 
PRACTICE THE BEST MODE

According to the approach used by the court in Chem-
cast Corp. v. Arco Industries, 913 F.2d 923, 16 USPQ2d 
1033 (Fed. Cir. 1990), a proper best mode analysis has two 
components:

(A)	Determine whether, at the time the application was 
filed, the inventor knew of a mode of practicing the claimed 
invention that the inventor considered to be better than any 
other.

The first component is a subjective inquiry because it 
focuses on the inventor's state of mind at the time the appli-
cation was filed. Unless the examiner has evidence that the 
inventors had information in their possession

(1)	at the time the application was filed

(2)	that a mode was considered to be better than 
any others by the inventors

	there is no reason to address the second compo-
nent and there is no proper basis for a best mode rejection. 
If the facts satisfy the first component, then, and only then, 
is the following second component analyzed:

(B)	Compare what was known in (A) with what was 
disclosed - is the disclosure adequate to enable one skilled 
in the art to practice the best mode?

Assessing the adequacy of the disclosure in this regard is 
largely an objective inquiry that depends on the level of 
skill in the art. Is the information contained in the specifica-
tion disclosure sufficient to enable a person skilled in the 
relevant art to make and use the best mode?

A best mode rejection is proper only when the first 
inquiry can be answered in the affirmative, and the second 
inquiry answered in the negative with reasons to support 
the conclusion that the specification is nonenabling with 
respect to the best mode.

2165.04	Examples of Evidence of  
Concealment 

In determining the adequacy of a best mode disclosure, 
only evidence of concealment (accidental or intentional) is 
to be considered. That evidence must tend to show that the 
quality of an applicant's best mode disclosure is so poor as 
to effectively result in concealment. 

I.	EXAMPLES - BEST MODE REQUIREMENT 
SATISFIED

In one case, even though the inventor had more informa-
tion in his possession concerning the contemplated best 
mode than was disclosed (a known computer program) the 
specification was held to delineate the best mode in a man-
ner sufficient to require only the application of routine skill 
to produce a workable digital computer program. In re 
Sherwood, 613 F.2d 809, 204 USPQ 537 (CCPA 1980).

In another case, the claimed subject matter was a time 
controlled thermostat, but the application did not disclose 
the specific Quartzmatic motor which was used in a com-
mercial embodiment. The Court concluded that failure to 
disclose the commercial motor did not amount to conceal-
ment since similar clock motors were widely available and 
widely advertised. There was no evidence that the specific 
Quartzmatic motor was superior except possibly in price. 
Honeywell v. Diamond, 208 USPQ 452 (D.D.C. 1980).

There was held to be no violation of the best mode 
requirement even though the inventor did not disclose the 
only mode of calculating the stretch rate for plastic rods 
that he used because that mode would have been employed 
by those of ordinary skill in the art at the time the applica-
tion was filed. W.L. Gore & Assoc., Inc. v. Garlock Inc., 
721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983).

There was no best mode violation where there was no 
evidence that the monoclonal antibodies used by the inven-
tors differed from those obtainable according to the pro-
cesses described in the specification. It was not disputed 
that the inventors obtained the antibodies used in the inven-
tion by following the procedures in the specification, that 
these were the inventors' preferred procedures, and that the 
data reported in the specification was for the antibody that 
the inventors had actually used. Scripps Clinic and 
Research Foundation v. Genentech, Inc., 927 F.2d 1565, 18 
USPQ 2d 1001 (Fed. Cir. 1991).

Where an organism was created by the insertion of 
genetic material into a cell obtained from generally avail-
able sources, all that was required to satisfy the best mode 
requirement was an adequate description of the means for 
carrying out the invention, not deposit of the cells. As to the 
observation that no scientist could ever duplicate exactly 
the cell used by applicants, the court observed that the issue 
is whether the disclosure is adequate, not that an exact 
duplication is necessary.  Amgen, Inc. v. Chugai Pharma-
ceutical Co., 927 F.2d 1200, 18 USPQ 2d 1016 (Fed. Cir. 
1991).

There was held to be no violation of the best mode 
requirement where the Solicitor argued that concealment 
could be inferred from the disclosure in a specification that 
each analog is "surprisingly and unexpectedly more useful 
than one of the corresponding prostaglandins . . . for at least 
one of the pharmacological purposes." It was argued that 
appellant must have had test results to substantiate this 
statement and this data should have been disclosed. The 
court concluded that no withholding could be inferred from 
general statements of increased selectivity and narrower 
spectrum of potency for these novel analogs, conclusions 
which could be drawn from the elementary pharmacologi-
cal testing of the analogs.  In re Bundy, 642 F.2d 430, 435, 
209 USPQ 48, 52 (CCPA 1981).

II.	EXAMPLES - BEST MODE REQUIREMENT 
NOT SATISFIED

The best mode requirement was held to be violated 
where inventors of a laser failed to disclose details of their 
preferred TiCuSil brazing method which were not con-
tained in the prior art and were contrary to criteria for the 
use of TiCuSil as contained in the literature.  Spectra-Phys-
ics, Inc. v. Coherent, Inc., 827 F.2d 1524, 3 USPQ 2d 1737 
(Fed. Cir. 1987).

The best mode requirement was violated because an 
inventor failed to disclose whether to use a specific surface 
treatment that he knew was necessary to the satisfactory 
performance of his invention, even though how to perform 
the treatment itself was known in the art. The argument that 
the best mode requirement may be met solely by reference 
to what was known in the prior art was rejected as incor-
rect. Dana Corp. v. IPC Ltd. Partnership, 860 F.2d 415, 8 
USPQ2d 1692 (Fed. Cir. 1988). 

2171	Two Separate Requirements for 
Claims Under 35 U.S.C. 112, Second 
Paragraph 

The second paragraph of 35 U.S.C. 112 is directed to 
requirements for the claims:

The specification shall conclude with one or more claims particu-
larly pointing out and distinctly claiming the subject matter 
which the applicant regards as his invention.

There are two separate requirements set forth in this 
paragraph:

(A)	the claims must set forth the subject matter that  
applicants regard as their invention; and 

(B)	the claims must particularly point out and dis-
tinctly define the metes and bounds of the subject matter 
that will be protected by the patent grant.

The first requirement is a subjective one because it is 
dependent on what the applicants for a patent regard as 
their invention. The second requirement is an objective one 
because it is not dependent on the views of applicant or any 
particular individual, but is evaluated in the context of 
whether the claim is definite - i.e., whether the scope of 
the claim is clear to a hypothetical person possessing the 
ordinary level of skill in the pertinent art.

Although an essential purpose of the examination pro-
cess is to determine whether or not the claims define an 
invention that is both novel and nonobvious over the prior 
art, another essential purpose of patent examination is to 
determine whether or not the claims are precise, clear, cor-
rect, and unambiguous. The uncertainties of claim scope 
should be removed, as much as possible, during the exami-
nation process.

The inquiry during examination is patentability of the 
invention as applicant regards it. If the claims do not partic-
ularly point out and distinctly claim that which applicants 
regard as their invention, the appropriate action by the 
examiner is to reject the claims under  35 U.S.C. 112, sec-
ond paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 
(Fed. Cir. 1989). If a rejection is based on  35 U.S.C. 112, 
second paragraph, the examiner should further explain 
whether the rejection is based on indefiniteness or on the 
failure to claim what applicants regard as their invention. 
Ex parte Ionescu, 222 USPQ 537, 539 (Bd. App. 1984).

2172	Subject Matter Which Applicants 
Regard as Their Invention

I.	FOCUS FOR EXAMINATION

A rejection based on the failure to satisfy this require-
ment is appropriate only where applicant has stated, some-
where other than in the application as filed, that the 
invention is something different from what is de fined by 
the claims. In other words, the invention set forth in the 
claims must be presumed, in the absence of evidence to the 
contrary, to be that which applicants regard as their inven-
tion. In re Moore, 439 F.2d 1232, 169 USPQ 236 (CCPA 
1971).

II.	EVIDENCE TO THE CONTRARY

Evidence that shows that a claim does not correspond in 
scope with that which applicant regards as applicant's 
invention may be found, for example, in contentions or 
admissions contained in briefs or remarks filed by appli-
cant, In re Prater, 415 F.2d 1393, 162 USPQ 541 (CCPA 
1969), or in affidavits filed under  37 CFR 1.132, In re Cor-
many, 476 F.2d 998, 177 USPQ 450 (CCPA 1973). The 
content of applicant's specification is not used as evidence 
that the scope of the claims is inconsistent with the subject 
matter which applicants regard as their invention. As noted 
in In re Ehrreich, 590 F.2d 902, 200 USPQ 504 (CCPA 
1979), agreement, or lack thereof, between the claims and 
the specification is properly considered only with respect to  
35 U.S.C. 112, first paragraph; it is irrelevant to compliance 
with the second paragraph of that section.

III.	SHIFT IN CLAIMS PERMITTED

The second paragraph of 35 U.S.C. 112 does not prohibit 
applicants from changing what they regard as their inven-
tion during the pendency of the application. In re Saunders, 
444 F.2d 599, 170 USPQ 213 (CCPA 1971) (Applicant was 
permitted to claim and submit comparative evidence with 
respect to claimed subject matter which originally was only 
the preferred embodiment within much broader claims 
(directed to a method).). The fact that claims in a continua-
tion application were directed to originally disclosed sub-
ject matter which applicants had not regarded as part of 
their invention when the parent application was filed was 
held not to prevent the continuation application from 
receiving benefits of the filing date of the parent applica-
tion under  35 U.S.C. 120. In re Brower, 433 F.2d 813, 167 
USPQ 684 (CCPA 1970).

2172.01	Unclaimed Essential Matter

A claim which omits matter disclosed to be essential to 
the invention as described in the specification or in other 
statements of record may be rejected under 35 U.S.C. 112, 
first paragraph, as not enabling. In re Mayhew, 527 F.2d 
1229, 188 USPQ 356 (CCPA 1976).  See also MPEP 
? 2164.08(c).  Such essential matter may include missing 
elements, steps or necessary structural cooperative relation-
ships of elements described by the applicant(s) as necessary 
to practice the invention.

In addition, a claim which fails to interrelate essential 
elements of the invention as defined by applicant(s) in the 
specification may be rejected under 35 U.S.C. 112, second 
paragraph, for failure to point out and distinctly claim the 
invention.  See In re Venezia, 530 F.2d 956, 189 USPQ 149 
(CCPA 1976); In re Collier, 397 F.2d 1003, 158 USPQ 266 
(CCPA 1968).

2173	Claims Must Particularly Point Out 
and Distinctly Claim the Invention

The primary purpose of this requirement of definiteness 
of claim language is to ensure that the scope of the claims is 
clear so the public is informed of the boundaries of what 
constitutes infringement of the patent. A secondary purpose 
is to provide a clear measure of what applicants regard as 
the invention so that it can be determined whether the 
claimed invention meets all the criteria for patentability and 
whether the specification meets the criteria of 35 U.S.C. 
112, first paragraph with respect to the claimed invention.

2173.01	Claim Terminology

A fundamental principle contained in 35 U.S.C. 112, 
second paragraph is that applicants are their own lexicogra-
phers. They can define in the claims what they regard as 
their invention essentially in whatever terms they choose so 
long as the terms are not used in ways that are contrary to 
accepted meanings in the art. Applicant may use functional 
language, alternative expressions, negative limitations, or 
any style of expression or format of claim which makes 
clear the boundaries of the subject matter for which protec-
tion is sought. As noted by the Court in In re Swinehart, 
439 F.2d 210, 160 USPQ 226 (CCPA 1971), a claim may 
not be rejected solely because of the type of language used 
to define the subject matter for which patent protection is 
sought.

2173.02	Clarity and Precision

The examiner's focus during examination of claims for 
compliance with the requirement for definiteness of 
35 U.S.C. 112, second paragraph is whether the claim 
meets the threshold requirements of clarity and precision, 
not whether more suitable language or modes of expression 
are available. When the examiner is satisfied that patent-
able subject matter is disclosed, and it is apparent to the 
examiner that the claims are directed to such patentable 
subject matter, he or she should allow claims which define 
the patentable subject matter with a reasonable degree of 
particularity and distinctness. Some latitude in the manner 
of expression and the aptness of terms should be permitted 
even though the claim language is not as precise as the 
examiner might desire. Examiners are encouraged to sug-
gest claim language to applicants to improve the clarity or 
precision of the language used, but should not reject claims 
or insist on their own preferences if other modes of expres-
sion selected by applicants satisfy the statutory require-
ment.

The essential inquiry pertaining to this requirement is 
whether the claims set out and circumscribe a particular 
subject matter with a reasonable degree of clarity and par-
ticularity. Definiteness of claim language must be analyzed, 
not in a vacuum, but in light of:

(A)	The content of the particular application disclo-
sure; 

(B)	The teachings of the prior art; and

(C)	The claim interpretation that would be given 	by 
one possessing the ordinary level of skill in the pertinent art 
at the time the invention was made. 

If the scope of the invention sought to be patented cannot 
be determined from the language of the claims with a rea-
sonable degree of certainty, a rejection of the claims under  
35 U.S.C. 112, second paragraph is appropriate. In re Wig-
gins, 488 F.2d 538, 179 USPQ 421 (CCPA 1973).

2173.03	Inconsistency Between Claim and 
Specification Disclosure or Prior  
Art

Although the terms of a claim may appear to be definite, 
inconsistency with the specification disclosure or prior art 
teachings may make an otherwise definite claim take on an 
unreasonable degree of uncertainty. In re Cohn, 438 F.2d 
989, 169 USPQ 95 (CCPA 1971); In re Hammack, 427 F.2d 
1378, 166 USPQ 204 (CCPA 1970). In Cohn, the claim was 
directed to a process of treating a surface with a corroding 
solution until the metallic appearance is supplanted by an 
"opaque" appearance. Noting that no claim may be read 
apart from and independent of the supporting disclosure on 
which it is based, the court found that the description, defi-
nitions and examples set forth in the specification relating 
to the appearance of the surface after treatment were inher-
ently inconsistent and rendered the claim indefinite.

2173.04	Breadth Is Not Indefiniteness

Breadth of a claim is not to be equated with indefinite-
ness. In re Miller, 441 F.2d 689, 169 USPQ 597 (CCPA 
1971). If the scope of the subject matter embraced by the 
claims is clear, and if applicants have not otherwise indi-
cated that they intend the invention to be of a scope differ-
ent from that defined in the claims, then the claims comply 
with  35 U.S.C. 112, second paragraph.

Undue breadth of the claim may be addressed under dif-
ferent statutory provisions, depending on the reasons for 
concluding that the claim is too broad. If the claim is too 
broad because it does not set forth that which applicants 
regard as their invention as evidenced by statements out-
side of the application as filed, a rejection under 35 U.S.C. 
112, second paragraph would be appropriate. If the claim is 
too broad because it is not supported by the original 
description or by an enabling disclosure, a rejection under  
35 U.S.C. 112, first paragraph would be appropriate. If the 
claim is too broad because it reads on the prior art, a rejec-
tion under either  35 U.S.C. 102 or 103 would be appropri-
ate. 

2173.05	Specific Topics Related to Issues 
Under 35 U.S.C. 112, Second 
Paragraph

The following sections are devoted to a discussion of 
specific topics where issues under 35 U.S.C. 112, second 
paragraph have been addressed. These sections are not 
intended to be an exhaustive list of the issues that can arise 
under 35 U.S.C. 112, second paragraph, but are intended to 
provide guidance in areas that have been addressed with 
some frequency in recent examination practice. The court 
and Board decisions cited are representative. As with all 
appellate decisions, the results are largely dictated by the 
facts in each case. The use of the same language in a differ-
ent context may justify a different result.

2173.05(a)	New Terminology

THE MEANING OF EVERY TERM SHOULD BE 
APPARENT

The meaning of every term used in a claim should be 
apparent from the prior art or from the specification and 
drawings at the time the application is filed. Applicants 
need not confine themselves to the terminology used in the 
prior art, but are required to make clear and precise the 
terms that are used to define the invention whereby the 
metes and bounds of the claimed invention can be ascer-
tained. During patent examination, the pending claims must 
be given the broadest reasonable interpretation consistent 
with the specification. In re Prater, 415 F.2d 1393, 162 
USPQ 541 (CCPA 1969). See also MPEP ? 2111 - ? 
2111.01. When the specification states the meaning that a 
term in the claim is intended to have, the claim is examined 
using that meaning, in order to achieve a complete explora-
tion of the applicant's invention and its relation to the prior 
art. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 
1989).

THE REQUIREMENT FOR CLARITY AND PRECI-
SION MUST BE BALANCED WITH THE LIMITA-
TIONS OF THE LANGUAGE 

Courts have recognized that it is not only permissible, 
but often desirable, to use new terms that are frequently 
more precise in describing and defining the new invention. 
In re Fisher, 427 F.2d 833, 166 USPQ 18 (CCPA 1970). 
Although it is difficult to compare the claimed invention 
with the prior art when new terms are used that do not 
appear in the prior art, this does not make the new terms 
indefinite. 

New terms are often used when a new technology is in 
its infancy or is rapidly evolving. The requirements for 
clarity and precision must be balanced with the limitations 
of the language and the science. If the claims, read in light 
of the specification, reasonably apprise those skilled in the 
art both of the utilization and scope of the invention, and if 
the language is as precise as the subject matter permits, the 
statute (35 U.S.C. 112, second paragraph) demands no 
more. Shatterproof Glass Corp. v. Libbey Owens Ford Co., 
758 F.2d 613, 225 USPQ 634 (Fed. Cir. 1985) (interpreta-
tion of "freely supporting" in method claims directed to 
treatment of a glass sheet);   Hybritech, Inc. v. Monoclonal 
Antibodies, Inc., 802 F.2d 1367, 231 USPQ 81 (Fed. Cir. 
1986) (interpretation of a limitation specifying a numerical 
value for antibody affinity where the method of calculation 
was known in the art at the time of filing to be imprecise). 
This does not mean that the examiner must accept the best 
effort of applicant. If the proposed language is not consid-
ered as precise as the subject matter permits, the examiner 
should provide reasons to support the conclusion of indefi-
niteness and is encouraged to suggest alternatives that are 
free from objection.

A TERM MAY NOT BE GIVEN A MEANING 
REPUGNANT TO ITS USUAL MEANING

While a term used in the claims may be given a special 
meaning in the description of the invention, generally no 
term may be given a meaning repugnant to the usual mean-
ing of the term. In re Hill, 161 F.2d 367, 73 USPQ 482 
(CCPA 1947). However, it has been stated that consistent 
with the well-established axiom in patent law that a paten-
tee is free to be his or her own lexicographer, a patentee 
may use terms in a manner contrary to or inconsistent with 
one or more of their ordinary meanings. Hormone Research 
Foundation Inc. v. Genentech Inc., 904 F.2d 1558, 15 
USPQ2d 1039 (Fed. Cir. 1990). Accordingly, when there is 
more than one definition for a term, it is incumbent upon 
applicant to make clear which definition is being relied 
upon to claim the invention. Until the meaning of a term or 
phrase used in a claim is clear, a rejection under 35 U.S.C. 
112, second paragraph is appropriate. It is appropriate to 
compare the meaning of terms given in technical dictionar-
ies in order to ascertain the accepted meaning of a term in 
the art. In re Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 
1971).

2173.05(b)	Relative Terminology

The fact that claim language, including terms of degree, 
may not be precise, does not automatically render the claim 
indefinite under  35 U.S.C. 112, second paragraph. Seattle 
Box Co., v. Industrial Crating & Packing, Inc., 731 F.2d 
818, 221 USPQ 568 (Fed. Cir. 1984). Acceptability of the 
claim language depends on whether one of ordinary skill in 
the art would understand what is claimed, in light of the 
specification.

WHEN A TERM OF DEGREE IS PRESENT, DETER-
MINE WHETHER A STANDARD IS DISCLOSED 
OR WHETHER ONE OF ORDINARY SKILL IN THE 
ART WOULD BE APPRISED OF THE SCOPE OF 
THE CLAIM

When a term of degree is presented in a claim, first a 
determination is to be made as to whether the specification 
provides some standard for measuring that degree. If it does 
not, a determination is made as to whether one of ordinary 
skill in the art, in view of the prior art and the status of the 
art, would be nevertheless reasonably apprised of the scope 
of the invention. Even if the specification uses the same 
term of degree as in the claim, a rejection may be proper if 
the scope of the term is not understood when read in light 
of the specification. While, as a general proposition, broad-
ening modifiers are standard tools in claim drafting in order 
to avoid reliance on the doctrine of equivalents in infringe-
ment actions, when the scope of the claim is unclear a 
rejection under 35 U.S.C. 112, second paragraph is proper. 
See In re Wiggins, 488 F. 2d 538, 541, 179 USPQ 421, 423 
(CCPA 1973).

When relative terms are used in claims wherein the 
improvement over the prior art rests entirely upon size or 
weight of an element in a combination of elements, the ade-
quacy of the disclosure of a standard is of greater criticality.

REFERENCE TO AN OBJECT THAT IS VARIABLE 
MAY RENDER A CLAIM INDEFINITE

A claim may be rendered indefinite by reference to an 
object that is variable. For example, the Board has held that 
a limitation in a claim to a bicycle that recited "said front 
and rear wheels so spaced as to give a wheelbase that is 
between 58 percent and 75 percent of the height of the rider 
that the bicycle was designed for" was indefinite because 
the relationship of parts was not based on any known stan-
dard for sizing a bicycle to a rider, but on a rider of unspec-
ified build. Ex parte Brummer, 12 USPQ2d 1653 (Bd. Pat. 
App. & Inter. 1989). On the other hand, a claim limitation 
specifying that a certain part of a pediatric wheelchair be 
"so dimensioned as to be insertable through the space 
between the doorframe of an automobile and one of the 
seats" was held to be definite. Orthokinetics, Inc. v. Safety 
Travel Chairs, Inc., 806 F.2d 1565, 1 USPQ2d 1081 (Fed. 
Cir. 1986). The court stated that the phrase "so dimen-
sioned" is as accurate as the subject matter permits, noting 
that the patent law does not require that all possible lengths 
corresponding to the spaces in hundreds of different auto-
mobiles be listed in the patent, let alone that they be listed 
in the claims.

A.	"About"

The term "about" used to define the area of the lower 
end of a mold as between 25 to about 45% of the mold 
entrance was held to be clear, but flexible. Ex parte East-
wood, 163 USPQ 316 (Bd. App. 1968).  Similarly, in W.L. 
Gore & Associates, Inc. v. Garlock, Inc., 721 F.2d 1540, 
220 USPQ 303 (Fed. Cir. 1983), the court held that a limi-
tation defining the stretch rate of a plastic as "exceeding 
about 10% per second" is definite because infringement 
could clearly be assessed through the use of a stopwatch. 
However, the court held that claims reciting "at least about" 
were invalid for indefiniteness where there was close prior 
art and there was nothing in the specification, prosecution 
history, or the prior art to provide any indication as to what 
range of specific activity is covered by the term "about." 
Amgen, Inc.  v. Chugai Pharmaceutical Co., 927 F.2d 1200, 
18 USPQ2d 1016 (Fed. Cir. 1991).

B.	"Essentially"

The phrase "a silicon dioxide source that is essentially 
free of alkali metal" was held to be definite because the 
specification contained guidelines and examples that were 
considered sufficient to enable a person of ordinary skill in 
the art to draw a line between unavoidable impurities in 
starting materials and essential ingredients. In re Marosi, 
710 F.2d 799, 218 USPQ 289 (CCPA 1983). The court fur-
ther observed that it would be impractical to require appli-
cants to specify a particular number as a cutoff between 
their invention and the prior art.

C.	"Similar"

The term "similar" in the preamble of a claim that was 
directed to a nozzle "for high-pressure cleaning units or 
similar apparatus" was held to be indefinite since it was not 
clear what applicant intended to cover by the recitation 
"similar" apparatus. Ex parte Kristensen, 10 USPQ2d 1701 
(Bd. Pat. App. & Inter. 1989).

A claim in a design patent application which read: "The 
ornamental design for a feed bunk or similar structure as 
shown and described." was held to be indefinite because it 
was unclear from the specification what applicant intended 
to cover by the recitation of "similar structure." Ex parte 
Pappas, 23 USPQ2d 1636 (Bd. Pat. App. & Inter. 1992).

D.	"Substantially"

The term "substantially" is often used in conjunction 
with another term to describe a particular characteristic of 
the claimed invention. It is a broad term. In re Nehrenberg, 
280 F.2d 161, 126 USPQ 383 (CCPA 1960). The court held 
that the limitation "to substantially increase the efficiency 
of the compound as a copper extractant" was definite in 
view of the general guidelines contained in the specifica-
tion. In re Mattison, 509 F.2d 563, 184 USPQ 484 (CCPA 
1975). The court held that the limitation "which produces 
substantially equal E and H plane illumination patterns" 
was definite because one of ordinary skill in the art would 
know what was meant by "substantially equal." Andrew 
Corp. v. Gabriel Electronics, 847 F.2d 819, 6 USPQ2d 
2010 (Fed. Cir. 1988).

E.	"Type"

The addition of the word "type" to an otherwise definite 
expression (e.g., Friedel-Crafts catalyst) extends the scope 
of the expression so as to render it indefinite.   Ex parte 
Copenhaver, 109 USPQ 118 (Bd. App. 1955). Likewise, 
the phrase "ZSM-5-type aluminosilicate zeolites" was held 
to be indefinite because it was unclear what "type" was 
intended to convey. The interpretation was made more dif-
ficult by the fact that the zeolites defined in the dependent 
claims were not within the genus of the type of zeolites 
defined in the independent claim. Ex parte Attig, 7 
USPQ2d 1092 (Bd. Pat. App. & Inter. 1986).

F.	Other Terms

The phrases "relatively shallow," "of the order of," "the 
order of about 5mm," and "substantial portion" were held 
to be indefinite because the specification lacked some stan-
dard for measuring the degree intended and, therefore, 
properly rejected as indefinite under 35 U.S.C. 112, second 
paragraph. Ex parte Oetiker, 23 USPQ2d 1641 (Bd. Pat. 
App. & Inter. 1992). 

The term "or like material" in the context of the limita-
tion "coke, brick, or like material" was held to render the 
claim indefinite since it was not clear how the materials 
other than coke or brick had to resemble the two specified 
materials to satisfy the limitations of the claim. Ex parte 
Caldwell, 1906 C.D. 58 (Comm'r Pat. 1906).

The terms "comparable" and "superior" were held to be 
indefinite in the context of a limitation relating the charac-
teristics of the claimed material to other materials - "prop-
erties that are superior to those obtained with comparable" 
prior art materials. Ex parte Anderson, 21 USPQ2d 1241 
(Bd. Pat. App. & Inter. 1991). It was not clear from the 
specification which properties had to be compared and how 
comparable the properties would have to be to determine 
infringement issues. Further, there was no guidance as to 
the meaning of the term "superior."

2173.05(c)	Numerical Ranges and Amounts 
Limitations

Generally, the recitation of specific numerical ranges in 
a claim does not raise an issue of whether a claim is defi-
nite.

I.	NARROW AND BROADER RANGES IN THE 
SAME CLAIM

Use of a narrow numerical range that falls within a 
broader range in the same claim may render the claim 
indefinite when the boundaries of the claim are not discern-
ible. Description of examples and preferences is properly 
set forth in the specification rather than in the claims. If 
stated in the claims, examples and preferences lead to con-
fusion over the intended scope of a claim. In those 
instances where it is not clear whether the claimed nar-
rower range is a limitation, a rejection under  35 U.S.C. 
112, second paragraph should be made. The Examiner 
should analyze whether the metes and bounds of the claim 
are clearly set forth. Examples of claim language which 
have been held to be indefinite are (A) "a temperature of 
between 45 and 78 degrees Celsius, preferably between 50 
and 60 degrees Celsius"; and (B) "a predetermined quan-
tity, for example, the maximum capacity."

II.	OPEN-ENDED NUMERICAL RANGES

Open-ended numerical ranges should be carefully ana-
lyzed for definiteness. For example, when an independent 
claim recites a composition comprising "at least 20% 
sodium" and a dependent claim sets forth specific amounts 
of nonsodium ingredients which add up to 100%, appar-
ently to the exclusion of sodium, an ambiguity is created 
with regard to the "at least" limitation (unless the percent-
ages of the nonsodium ingredients are based on the weight 
of the nonsodium ingredients). On the other hand, the court 
held that a composition claimed to have a theoretical con-
tent greater than 100% (i.e., 20-80% of A, 20-80% of B, 
and 1-25% of C) was not indefinite simply because the 
claims may be read in theory to include compositions that 
are impossible in fact to formulate. It was observed that 
subject matter which cannot exist in fact can neither antici-
pate nor infringe a claim. In re Kroekel, 504 F.2d 1143, 183 
USPQ 610 (CCPA 1974).

In a claim directed to a chemical reaction process, a lim-
itation required that the amount of one ingredient in the 
reaction mixture should "be maintained at less than 7 mole 
percent" based on the amount of another ingredient. The 
examiner argued that the claim was indefinite because the 
limitation sets only a maximum amount and is inclusive of 
substantially no ingredient resulting in termination of any 
reaction. The court did not agree be cause the claim was 
clearly directed to a reaction process which did not warrant 
distorting the overall meaning of the claim to preclude per-
forming the claimed process. In re Kirsch, 498 F.2d 1389, 
182 USPQ 286 (CCPA 1974).

Some terms have been determined to have the following 
meanings in the factual situations of the reported cases: the 
term "up to" includes zero as a lower limit, In re Mochel, 
470 F.2d 638, 176 USPQ 194 (CCPA 1974); and "a mois-
ture content of not more than 70% by weight" reads on dry 
material, Ex parte Khusid, 174 USPQ 59 (Bd. App. 1971).

III.	"EFFECTIVE AMOUNT"

The common phrase "an effective amount" may or may 
not be indefinite. The proper test is whether or not one 
skilled in the art could determine specific values for the 
amount based on the disclosure. See In re Mattison, 509 
F.2d 563, 184 USPQ 484 (CCPA 1975). The phrase "an 
effective amount . . . for growth stimulation" was held to be 
definite where the amount was not critical and those skilled 
in the art would be able to determine from the written dis-
closure, including the examples, what an effective amount 
is. In re Halleck, 422 F.2d 911, 164 USPQ 647 (CCPA 
1970). The phrase "an effective amount" has been held to 
be indefinite when the claim fails to state the function 
which is to be achieved and more than one effect can be 
implied from the specification or the relevant art. In re Fre-
dericksen 213 F.2d 547, 102 USPQ 35 (CCPA 1954). The 
more recent cases have tended to accept a limitation such as 
"an effective amount" as being definite when read in light 
of the supporting disclosure and in the absence of any prior 
art which would give rise to uncertainty about the scope of 
the claim. In Ex parte Skuballa, 12 USPQ2d 1570 (Bd. Pat. 
App. & Inter. 1989), the Board held that a pharmaceutical 
composition claim which recited an "effective amount of a 
compound of claim 1" without stating the function to be 
achieved was definite, particularly when read in light of the 
supporting disclosure which provided guidelines as to the 
intended utilities and how the uses could be effected.

2173.05(d)	Exemplary Claim Language ("for 
example," "such as")

Description of examples or preferences is properly set 
forth in the specification rather than the claims. If stated in 
the claims, examples and preferences lead to confusion 
over the intended scope of a claim. In those instances where 
it is not clear whether the claimed narrower range is a limi-
tation, a rejection under 35 U.S.C. 112, second paragraph 
should be made. The Examiner should analyze whether the 
metes and bounds of the claim are clearly set forth. Exam-
ples of claim language which have been held to be indefi-
nite because the intended scope of the claim was unclear 
are: 

(A)	"R is halogen, for example, chlorine"; 

(B)	"material such as rock wool or asbestos" Ex parte 
Hall, 83 USPQ 38 (Bd. App. 1949); 

(C)	"lighter hydrocarbons, such, for example, as the 
vapors or gas produced" Ex parte Hasche, 86 USPQ 481 
(Bd. App. 1949); and 

(D)	"normal operating conditions such as while in the 
container of a proportioner" Ex parte Steigerwald, 131 
USPQ 74 (Bd. App. 1961).

2173.05(e)	Lack of Antecedent Basis

A claim is indefinite when it contains words or phrases 
whose meaning is unclear. The lack of clarity could arise 
where a claim refers to "said lever" or "the lever," where 
the claim contains no earlier recitation or limitation of a 
lever and where it would be unclear as to what element the 
limitation was making reference. Similarly, if two different 
levers are recited earlier in the claim, the recitation of "said 
lever" in the same or subsequent claim would be unclear 
where it is uncertain which of the two levers was intended. 
A claim which refers to "said aluminum lever," but recites 
only "a lever" earlier in the claim, is indefinite because it is 
uncertain as to the lever to which reference is made. Obvi-
ously, however, the failure to provide explicit antecedent 
basis for terms does not always render a claim indefinite. If 
the scope of a claim would be reasonably ascertainable by 
those skilled in the art, then the claim is not indefinite. Ex 
parte Porter, 25 USPQ2d 1144, 1145 (Bd. Pat. App. & 
Inter. 1992) ("controlled stream of fluid" provided reason-
able antecedent basis for "the controlled fluid"). Inherent 
components of elements recited have antecedent basis in 
the recitation of the components themselves. For example, 
the limitation "the outer surface of said sphere" would not 
require an antecedent recitation that the sphere has an outer 
surface.

EXAMINER SHOULD SUGGEST CORRECTIONS 
TO ANTECEDENT PROBLEMS

Antecedent problems in the claims are typically drafting 
oversights that are easily corrected once they are brought to 
the attention of applicant. The examiner's task of making 
sure the claim language complies with the requirements of 
the statute should be carried out in a positive and construc-
tive way, so that minor problems can be identified and eas-
ily corrected, and so that the major effort is expended on 
more substantive issues. However, even though indefinite-
ness in claim language is of semantic origin, it is not ren-
dered unobjectionable simply because it could have been 
corrected. In re Hammack, 427 F.2d 1384 n.5, 166 USPQ 
209 n.5 (CCPA 1970).

A CLAIM TERM WHICH HAS NO ANTECEDENT 
BASIS IN THE DISCLOSURE IS NOT NECESSAR-
ILY INDEFINITE

The mere fact that a term or phrase used in the claim has 
no antecedent basis in the specification disclosure does not 
mean, necessarily, that the term or phrase is indefinite. 
There is no requirement that the words in the claim must 
match those used in the specification disclosure. Applicants 
are given a great deal of latitude in how they choose to 
define their invention so long as the terms and phrases used 
define the invention with a reasonable degree of clarity and 
precision. 

2173.05(f)	Reference to Limitations in 
Another Claim

A claim which makes reference to a preceding claim to 
define a limitation is an acceptable claim construction 
which should not necessarily be rejected as improper or 
confusing under  35 U.S.C. 112, second paragraph. For 
example, claims which read: "The product produced by the 
method of claim 1." or "A method of producing ethanol 
comprising contacting amylose with the culture of claim 1 
under the following conditions ....." are not indefinite under  
35 U.S.C. 112, second paragraph, merely because of the 
reference to another claim. See also Ex parte Porter, 25 
USPQ2d 1144 (Bd. Pat. App. & Inter. 1992) where refer-
ence to "the nozzle of claim 7" in a method claim was held 
to comply with 35 U.S.C. 112, second paragraph. However, 
where the format of making reference to limitations recited 
in another claim results in confusion, then a rejection would 
be proper under 35 U.S.C. 112, second paragraph. 

2173.05(g)	Functional Limitations

A functional limitation is an attempt to define something 
by what it does, rather than by what it is (e.g., as evidenced 
by its specific structure or specific ingredients). There is 
nothing inherently wrong with defining some part of an 
invention in functional terms. Functional language does 
not, in and of itself, render a claim improper. In re Swine-
hart, 439 F.2d 210, 169 USPQ 226 (CCPA 1971). 

A functional limitation must be evaluated and consid-
ered, just like any other limitation of the claim, for what it 
fairly conveys to a person of ordinary skill in the pertinent 
art in the context in which it is used. A functional limitation 
is often used in association with an element, ingredient, or 
step of a process to define a particular capability or purpose 
that is served by the recited element, ingredient or step. 
Whether or not the functional limitation complies with 
35 U.S.C. 112, second paragraph is a different issue from 
whether the limitation is properly supported under 
35 U.S.C. 112, first paragraph or is distinguished over the 
prior art. A few examples are set forth below to illustrate 
situations where the issue of whether a functional limitation 
complies with 35 U.S.C. 112, second paragraph was con-
sidered.

It was held that the limitation used to define a radical on 
a chemical compound as "incapable of forming a dye with 
said oxidizing developing agent" although functional, was 
perfectly acceptable because it set definite boundaries on 
the patent protection sought. In re Barr, 444 F.2d 588, 170 
USPQ 33 (CCPA 1971).

In a claim that was directed to a kit of component parts 
capable of being assembled, the Court held that limitations 
such as "members adapted to be positioned" and "portions . 
. . being resiliently dilatable whereby said housing may be 
slidably positioned" serve to precisely define present struc-
tural attributes of interrelated component parts of the 
claimed assembly. In re Venezia, 530 F.2d 956, 189 USPQ 
149 (CCPA 1976).

2173.05(h)	Alternative Limitations

I.	MARKUSH GROUPS

Alternative expressions are permitted if they present no 
uncertainty or ambiguity with respect to the question of 
scope or clarity of the claims. One acceptable form of alter-
native expression, which is commonly referred to as a 
Markush group, recites members as being "selected from 
the group consisting of A, B and C." See Ex parte 
Markush, 1925 C.D. 126 (Comm'r Pat. 1925). 

Ex parte Markush sanctions claiming a genus expressed 
as a group consisting of certain specified materials. Inven-
tions in metallurgy, refractories, ceramics, pharmacy, phar-
macology and biology are most frequently claimed under 
the Markush formula but purely mechanical features or 
process steps may also be claimed by using the Markush 
style of claiming. See Ex parte Head, 214 USPQ 551 (Bd. 
App. 1981); In re Gaubert, 524 F.2d 1222, 187 USPQ 664 
(CCPA 1975); and In re Harnisch, 631 F.2d 716, 206 
USPQ 300 (CCPA 1980). It is improper to use the term 
"comprising" instead of "consisting of." Ex parte Dotter, 
12 USPQ 382 (Bd. App. 1931).

The use of Markush claims of diminishing scope should 
not, in itself, be considered a sufficient basis for objection 
to or rejection of claims. However, if such a practice ren-
ders the claims indefinite or if it results in undue multiplic-
ity, an appropriate rejection should be made.

Similarly, the double inclusion of an element by mem-
bers of a Markush group is not, in itself, sufficient basis for 
objection to or rejection of claims. Rather, the facts in each 
case must be evaluated to determine whether or not the 
multiple inclusion of one or more elements in a claim ren-
ders that claim indefinite. The mere fact that a compound 
may be embraced by more than one member of a Markush 
group recited in the claim does not necessarily render the 
scope of the claim unclear. For example, the Markush 
group, "selected from the group consisting of amino, halo-
gen, nitro, chloro and alkyl" should be acceptable even 
though "halogen" is generic to "chloro." 

The materials set forth in the Markush group ordinarily 
must belong to a recognized physical or chemical class or 
to an art-recognized class. However, when the Markush 
group occurs in a claim reciting a process or a combination 
(not a single compound), it is sufficient if the members of 
the group are disclosed in the specification to possess at 
least one property in common which is mainly responsible 
for their function in the claimed relationship, and it is clear 
from their very nature or from the prior art that all of them 
possess this property. While in the past the test for 
Markush-type claims was applied as liberally as possible, 
present practice which holds that claims reciting Markush 
groups are not generic claims (MPEP ? 803) may subject 
the groups to a more stringent test for propriety of the 
recited members. Where a Markush expression is applied 
only to a portion of a chemical compound, the propriety of 
the grouping is determined by a consideration of the com-
pound as a whole, and does not depend on there being a 
community of properties in the members of the Markush 
expression.

When materials recited in a claim are so related as to 
constitute a proper Markush group, they may be recited in 
the conventional manner, or alternatively. For example, if 
"wherein R is a material selected from the group consisting 
of A, B, C and D" is a proper limitation, then "wherein R is 
A, B, C or D" shall also be considered proper. 

Subgenus Claim

A situation may occur in which a patentee has presented 
a number of examples which, in the examiner's opinion, 
are sufficiently representative to support a generic claim 
and yet a court may subsequently hold the claim invalid on 
the ground of undue breadth. Where this happens the paten-
tee is often limited to species claims which may not provide 
him with suitable protection.

The allowance of a Markush-type claim under a true 
genus claim would appear to be beneficial to the applicant 
without imposing any undue burden on the Patent and 
Trademark Office or in any way detracting from the rights 
of the public. Such a subgenus claim would enable the 
applicant to claim all the disclosed operative embodiments 
and afford applicant an intermediate level of protection in 
the event the true genus claims should be subsequently held 
invalid.

The examiners are therefore instructed not to reject a 
Markush-type claim merely because of the presence of a 
true genus claim embracive thereof.

See also MPEP ? 608.01(p) and  ? 715.03.

See MPEP ? 803.02 for restriction practice re Markush-
type claims. 

II.	"OR" TERMINOLOGY

Alternative expressions using "or" are acceptable, such 
as "wherein R is A, B, C, or D." The following phrases 
were each held to be acceptable and not in violation of 
35 U.S.C. 112, second paragraph in In re Gaubert, 524 F.2d 
1222, 187 USPQ 664 (CCPA 1975): "made entirely or in 
part of"; "at least one piece"; and "iron, steel or any other 
magnetic material." 

III.	"OPTIONALLY"

An alternative format which requires some analysis 
before concluding whether or not the language is indefinite 
involves the use of the term "optionally." In Ex parte Cor-
dova, 10 USPQ2d 1949 (Bd. Pat. App. & Inter. 1989) the 
language "containing A, B, and optionally C" was consid-
ered acceptable alternative language because there was no 
ambiguity as to which alternatives are covered by the 
claim. A similar holding was reached with regard to the 
term "optionally" in Ex parte Wu, 10 USPQ2d 2031 (Bd. 
Pat. App. & Inter. 1989). In the instance where the list of 
potential alternatives can vary and ambiguity arises, then it 
is proper to make a rejection under 35 U.S.C. 112, second 
paragraph and explain why there is confusion.

2173.05(i)	Negative Limitations

The current view of the courts is that there is nothing 
inherently ambiguous or uncertain about a negative limita-
tion. So long as the boundaries of the patent protection 
sought are set forth definitely, albeit negatively, the claim 
complies with the requirements of 35 U.S.C. 112, second 
paragraph. Some older cases were critical of negative limi-
tations because they tended to define the invention in terms 
of what it was not, rather than pointing out the invention. 
Thus, the court observed that the limitation "R is an alkenyl 
radical other than 2-butenyl and 2,4-pentadienyl" was a 
negative limitation that rendered the claim indefinite 
because it was an attempt to claim the invention by exclud-
ing what the inventors did not invent rather than distinctly 
and particularly pointing out what they did invent. In re 
Schechter, 205 F.2d 185, 98 USPQ 144 (CCPA 1953).

A claim which recited the limitation "said homopolymer 
being free from the proteins, soaps, resins, and sugars 
present in natural Hevea rubber" in order to exclude the 
characteristics of the prior art product, was considered defi-
nite because each recited limitation was definite. In re 
Wakefield, 422 F.2d 897, 899, 904, 164 USPQ 636, 638, 
641 (CCPA 1970). In addition, the court found that the neg-
ative limitation "incapable of forming a dye with said oxi-
dized developing agent" was definite because the 
boundaries of the patent protection sought were clear.  In re 
Barr, 444 F.2d 588, 170 USPQ 330 (CCPA 1971).

Any negative limitation or exclusionary proviso must 
have basis in the original disclosure. See Ex parte Gras-
selli, 231 USPQ 393 (Bd. App. 1983), aff'd mem., 738 F.2d 
453 (Fed. Cir. 1984). The mere absence of a positive recita-
tion is not basis for an exclusion. Any claim containing a 
negative limitation which does not have basis in the origi-
nal disclosure should be rejected under 35 U.S.C. 112, first 
paragraph as failing to comply with the written description 
requirement. Note that a lack of literal basis in the specifi-
cation for a negative limitation may not be sufficient to 
establish a prima facie case for lack of descriptive support. 
Ex parte Parks, 30 USPQ2d  1234, 1236 (Bd. Pat. App. & 
Inter. 1993). See MPEP ? 2163 - ? 2163.07(b) for a discus-
sion of the written description requirement of 35 U.S.C. 
112, first paragraph.

2173.05(j)	Old Combination

A CLAIM SHOULD NOT BE REJECTED ON THE 
GROUND OF OLD COMBINATION

With the passage of the 1952 Patent Act, the courts and 
the Board have taken the view that a rejection based on the 
principle of old combination is NO LONGER VALID. 
Claims should be considered proper so long as they comply 
with the provisions of  35 U.S.C. 112, second paragraph. 

A rejection on the basis of old combination was based on 
the principle applied in Lincoln Engineering Co. v. Stewart-
Warner Corp., 303 U.S. 545, 37 USPQ 1 (1938). The prin-
ciple was that an inventor who made an improvement or 
contribution to but one element of a generally old combina-
tion, should not be able to obtain a patent on the entire 
combination including the new and improved element. A 
rejection required the citation of a single reference which 
broadly disclosed a combination of the claimed elements 
functionally cooperating in substantially the same manner 
to produce substantially the same results as that of the 
claimed combination. The case of In re Hall, 208 F.2d 370, 
100 USPQ 46 (CCPA 1953) illustrates an application of 
this principle.

The court pointed out in In re Bernhardt, 417 F.2d 1395, 
163 USPQ 611 (CCPA 1969) that the statutory language 
(particularly point out and distinctly claim) is the only 
proper basis for an old combination rejection, and in apply-
ing the rejection, that language determines what an appli-
cant has a right and obligation to do. A majority opinion of 
the Board of Appeals held that Congress removed the 
underlying rationale of Lincoln Engineering in the 1952 
Patent Act, and thereby effectively legislated that decision 
out of existence. Ex parte Barber, 187 USPQ 244 (Bd. 
App. 1974). Finally, the Court of Appeals for the Federal 
Circuit, in Radio Steel and Mfg. Co. v. MTD Products, Inc., 
731 F.2d 840, 221 USPQ 657 (Fed. Cir. 1984), followed the 
Bernhardt case, and ruled that a claim was not invalid 
under Lincoln Engineering because the claim complied 
with the requirements of 35 U.S.C. 112, second paragraph. 
Accordingly, a claim should not be rejected on the ground 
of old combination.

2173.05(k)	Aggregation

Rejections on the ground of aggregation should be based 
upon a lack of cooperation between the elements of the 
claim.

Example of aggregation: A washing machine associated 
with a dial telephone.

A claim is not necessarily aggregative because the vari-
ous elements do not function simultaneously, e.g., a type-
writer. In re Worrest, 201 F.2d 930, 96 USPQ 381 (CCPA 
1953). Neither is a claim necessarily aggregative merely 
because elements which do cooperate are set forth in spe-
cific detail.

A rejection on aggregation should be made only after 
consideration of the court's comments in In re Gustafson, 
331 F.2d 905, 141 USPQ 585 (CCPA 1964), wherein the 
court indicated it is improper to reject claims as "aggrega-
tive" without specifying the statutory basis of the rejection, 
i.e., an applicant is entitled to know whether his claims are 
being rejected under 35 U.S.C. 101, 103, or 112. In 
Gustafson, the court found that the real objection to the 
claims was that they failed to comply with 35 U.S.C. 112, 
second paragraph.

2173.05(m)	Prolix

Examiners should reject claims as prolix only when they 
contain such long recitations or unimportant details that the 
scope of the claimed invention is rendered indefinite 
thereby. Claims are rejected as prolix when they contain 
long recitations or unimportant details which hide or 
obscure the invention.  Ex parte Iagan, 1911 C.D. 10, 162 
O.G. 538 (Comm'r Pat. 1910), expresses the thought that 
very long detailed claims setting forth so many elements 
that invention cannot possibly reside in the combination 
should be rejected as prolix. See also In re Ludwick, 4 F.2d 
959, 1925 C.D. 306, 339 O.G. 393 (D.C. Cir. 1925). 

2173.05(n)	Multiplicity

37 CFR 1.75.  Claim(s).

(a)	The specification must conclude with a claim particularly point-
ing out and distinctly claiming the subject matter which the applicant 
regards as his invention or discovery.

(b)	More than one claim may be presented provided they differ sub-
stantially from each other and are not unduly multiplied.

(c)	One or more claims may be presented in dependent form, refer-
ring back to and further limiting another claim or claims in the same appli-
cation. Any dependent claim which refers to more than one other claim 
("multiple dependent claim") shall refer to such other claims in the alter-
native only. A multiple dependent claim shall not serve as a basis for any 
other multiple dependent claim. For fee calculation purposes under ? 1.16, 
a multiple dependent claim will be considered to be that number of claims 
to which direct reference is made therein. For fee calculation purposes, 
also, any claim depending from a multiple dependent claim will be consid-
ered to be that number of claims to which direct reference is made in that 
multiple dependent claim. In addition to the other filing fees, any original 
application which is filed with, or is amended to include, multiple depen-
dent claims must have paid the fee set forth in ? 1.16(d). Claims in depen-
dent form shall be construed to include all the limitations of the claim 
incorporated by reference into the dependent claim. A multiple dependent 
claim shall be construed to incorporate by reference all the limitations of 
each of the particular claims In relation to which it is being considered.

(d)	(1) The claim or claims must conform to the invention as set 
forth in the remainder of the specification and the terms and phrases used 
in the claims must find clear support or antecedent basis in the description 
so that the meaning of the terms may be ascertained by reference to the 
description (See ? 1.58(a)).

(2)	See ?? 1.141 to 1.146 as to claiming different inventions in 
one application.

(e)	Where the nature of the case admits, as in the case of an 
improvement, any independent claim should contain in the following 
order, (1) a preamble comprising a general description of all elements or 
steps of the claimed combination which are conventional or known, (2) a 
phrase such as "wherein the improvement comprises," and (3) those ele-
ments, steps, and/or relationships which constitute that portion of the 
claimed combination which the applicant regards as the new or improved 
portion.

(f)	If there are several claims, they shall be numbered consecutively 
in Arabic numerals.

(g)	The least restrictive claim should be presented as claim number 
1, and all dependent claims should be grouped together with the claim or 
claims to which they refer to the extent practicable.

(h)	The claim or claims must commence on a separate sheet.

(i)	Where a claim sets forth a plurality of elements or steps, each 
element or step of the claim should be separated by a line indentation.

An unreasonable number of claims, that is, unreasonable 
in view of the nature and scope of applicant's invention and 
the state of the art, may afford a basis for a rejection on the 
ground of multiplicity. A rejection on this ground should 
include all the claims in the case inasmuch as it relates to 
confusion of the issue.

To avoid the possibility that an application which has 
been rejected on the ground of undue multiplicity of claims 
may be appealed to the Board of Patent Appeals and Inter-
ferences prior to an examination on the merits of at least 
some of the claims presented, the examiner should, at the 
time of making the rejection on the ground of multiplicity 
of claims, specify the number of claims which in his or her 
judgment is sufficient to properly define applicant's inven-
tion and require the applicant to select certain claims, not to 
exceed the number specified, for examination on the mer-
its. The examiner should be reasonable in setting the num-
ber to afford the applicant some latitude in claiming the 
invention. 

The earlier views of the Court of Customs and Patent 
Appeals on multiplicity were set forth in In re Chandler, 
254 F.2d 396, 117 USPQ 361 (1958) and In re Chandler, 
319 F.2d 211, 225, 138 USPQ 138, 148  (1963) (Appli-
cant's latitude in stating their claims in regard to number 
and phraseology employed "should not be extended to 
sanction that degree of repetition and multiplicity which 
beclouds definition in a maze of confusion."). These views 
have been somewhat revised by its views in In re Flint, 411 
F.2d 1353, 1357, 162 USPQ 228, 231 (CCPA 1969) ("The 
[42] claims differed from one another and we have no diffi-
culty in understanding the scope of protection. Nor is it 
clear, on this record, that the examiner or board was con-
fused by the presentation of claims in this case or that the 
public will be.") and In re Wakefield, 422 F.2d 897, 902, 
164 USPQ 636, 639 (CCPA 1970) ("Examination of forty 
claims in a single application may be tedious work, but this 
is no reason for saying that the invention is obscured by the 
large number of claims. We note that the claims were clear 
enough for the examiner to apply references against all of 
them in his first action."). 

If a rejection on multiplicity is in order the examiner 
should make a telephone call explaining that the claims are 
unduly multiplied and will be rejected on that ground. Note  
MPEP ? 408. The examiner should request selection of a 
specified number of claims for purposes of examination.

If time for consideration is requested arrangements 
should be made for a second telephone call, preferably 
within three working days.

When claims are selected, a formal multiplicity rejection 
is made, including a complete record of the telephone inter-
view, followed by an action on the selected claims.

When applicant refuses to comply with the telephone 
request, a formal multiplicity rejection is made. The appli-
cant's reply to a formal multiplicity rejection of the exam-
iner, to be complete, must either:

(A)	Reduce the number of claims presented to those 
selected previously by telephone, or if no previous selec-
tion has been made to a number not exceeding the number 
specified by the examiner in the Office action, thus over-
coming the rejection based upon the ground of multiplicity, 
or

(B)	In the event of a traverse of said rejection appli-
cant, besides specifically pointing out the supposed errors 
of the multiplicity rejection, is required to confirm the 
selection previously made by telephone, or if no previous 
selection has been made, select certain claims for purpose 
of examination, the number of which is not greater than the 
number specified by the examiner.

If the rejection on multiplicity is adhered to, all claims 
retained will be included in such rejection and the selected 
claims only will be additionally examined on their merits. 
This procedure preserves applicant's right to have the rejec-
tion on multiplicity reviewed by the Board of Patent 
Appeals and Interferences. 

Also, it is possible to reject one claim on an allowed 
claim if they differ only by subject matter old in the art. 
This ground of rejection is set forth in Ex parte Whitelaw, 
1915 C.D. 18, 219 O.G. 1237 (Comm'r Pat. 1914). The Ex 
parte Whitelaw doctrine is restricted to cases where the 
claims are unduly multiplied or are substantial duplicates. 
Ex parte Kochan, 131 USPQ 204, 206 (Bd. App. 1961).

2173.05(o)	Double Inclusion

While the concept that double inclusion of an element in 
members of a Markush group recited in a claim is, per se, 
objectionable and renders a claim indefinite is supported by 
some of the older cases like Ex parte White, 759 O.G. 783 
(Bd. App. 1958) and Ex parte Clark, 174 USPQ 40 (Bd. 
App. 1971), other decisions clearly hold that there is no per 
se rule of indefiniteness concerning overlapping members 
where alternatives are recited in a claim, e.g., members of a 
Markush group. In re Kelly, 305 F.2d 909, 134 USPQ 397 
(CCPA 1962).

The facts in each case must be evaluated to determine 
whether or not the multiple inclusion of one or more ele-
ments in a claim gives rise to indefiniteness in that claim. 
The mere fact that a compound may be embraced by more 
than one member of a Markush group recited in the claim 
does not lead to any uncertainty as to the scope of that 
claim for either examination or infringement purposes. On 
the other hand, where a claim directed to a device can be 
read to include the same element twice, the claim may be 
indefinite. Ex parte Kristensen, 10 USPQ2d 1701 (Bd. Pat. 
App. & Inter. 1989).

2173.05(p)	Claim Directed to Product-By- 
Process or Product and Process

I.	PRODUCT-BY-PROCESS

There are many situations where claims are permissively 
drafted to include a reference to more than one statutory 
class of invention. A product-by-process claim, which is a 
product claim that defines the claimed product in terms of 
the process by which it is made, is proper. In re Moeller, 
117 F.2d 565, 48 USPQ 542 (CCPA 1941); In re Luck, 476 
F.2d 650, 177 USPQ 523 (CCPA 1973); In re Steppan, 394 
F.2d 1013, 156 USPQ 143 (CCPA 1967); and In re Pilking-
ton, 411 F.2d 1345, 162 USPQ 145 (CCPA 1969). A claim 
to a device, apparatus, manufacture, or composition of mat-
ter may contain a reference to the process in which it is 
intended to be used without being objectionable under 
35 U.S.C. 112, second paragraph, so long as it is clear that 
the claim is directed to the product and not the process.

The fact that it is necessary for an applicant to describe 
his product in product-by-process terms does not prevent 
him from presenting claims of varying scope. Ex parte 
Pantzer, 176 USPQ 141 (Bd. App. 1972).

II.	PRODUCT AND PROCESS IN THE SAME 
CLAIM

A single claim which claims both an apparatus and the 
method steps of using the apparatus is indefinite under 
35 U.S.C. 112, second paragraph. In Ex parte Lyell, 17 
USPQ2d 1548 (Bd. Pat. App. & Inter. 1990), a claim 
directed to an automatic transmission workstand and the 
method steps of using it was held to be ambiguous and 
properly rejected under 35 U.S.C. 112, second paragraph.

Such claims should also be rejected under 35 U.S.C. 101 
based on the theory that the claim is directed to neither a 
"process" nor a "machine," but rather embraces or overlaps 
two different statutory classes of invention set forth in 
35 U.S.C. 101 which is drafted so as to set forth the statu-
tory classes of invention in the alternative only. Id. at 1551. 

2173.05(q)	"Use" Claims

Attempts to claim a process without setting forth any 
steps involved in the process generally raises an issue of 
indefiniteness under 35 U.S.C. 112, second paragraph. For 
example, a claim which read: "A process for using mono-
clonal antibodies of claim 4 to isolate and purify human 
fibroblast interferon." was held to be indefinite because it 
merely recites a use without any active, positive steps 
delimiting how this use is actually practiced. Ex parte 
Erlich, 3 USPQ2d 1011 (Bd. Pat. App. & Inter. 1986). 

Other decisions suggest that a more appropriate basis for 
this type of rejection is  35 U.S.C. 101. In Ex parte Dunki, 
153 USPQ 678 (Bd. App. 1967), the Board held the follow-
ing claim to be an improper definition of a process: "The 
use of a high carbon austenitic iron alloy having a propor-
tion of free carbon as a vehicle brake part subject to stress 
by sliding friction." In Clinical Products Ltd. v. Brenner, 
255 F. Supp. 131, 149 USPQ 475 (D.D.C. 1966), the dis-
trict court held the following claim was definite, but that it 
was not a proper process claim under  35 U.S.C. 101: "The 
use of a sustained release therapeutic agent in the body of 
ephedrine absorbed upon polystyrene sulfonic acid." 

Although a claim should be interpreted in light of the 
specification disclosure, it is generally considered improper 
to read limitations contained in the specification into the 
claims. See In re Prater, 415 F.2d 1393, 162 USPQ 541 
(CCPA 1969) and In re Winkhaus, 527 F.2d 637, 188 USPQ 
129 (CCPA 1975), which discuss the premise that one can-
not rely on the specification to impart limitations to the 
claim that are not recited in the claim. 

A "USE" CLAIM SHOULD BE REJECTED UNDER 
ALTERNATIVE GROUNDS BASED ON 35 U.S.C 101 
AND 112

In view of the split of authority as discussed above, the 
most appropriate course of action would be to reject a "use" 
claim under alternative grounds based on 35 U.S.C. 101 
and 112.

BOARD HELD STEP OF "UTILIZING" WAS NOT 
INDEFINITE

It is often difficult to draw a fine line between what is 
permissible, and what is objectionable from the perspective 
of whether a claim is definite. In the case of Ex parte Por-
ter, 25 USPQ2d 1144 (Bd. Pat. App. & Inter. 1992), the 
Board held that a claim which clearly recited the step of 
"utilizing" was not indefinite under 35 U.S.C. 112, second 
paragraph. (Claim was to "A method for unloading non-
packed, nonbridging and packed, bridging flowable particle 
catalyst and bead material from the opened end of a reactor 
tube which comprises utilizing the nozzle of claim 7.").

2173.05(r)	Omnibus Claim

Some applications are filed with an omnibus claim 
which reads as follows: A device substantially as shown 
and described. This claim should be rejected under 
35 U.S.C. 112, second paragraph because it is indefinite in 
that it fails to point out what is included or excluded by the 
claim language. See Ex parte Fressola, 27 USPQ2d 1608 
(Bd. Pat. App. & Inter. 1993), for a discussion of the his-
tory of omnibus claims and an explanation of why omnibus 
claims do not comply with the requirements of 35 U.S.C. 
112, second paragraph.

Such a claim can be rejected using Form Paragraph 7.35.  
See  MPEP ? 706.03(d). 

For cancelation of such a claim by examiner's amend-
ment, see  MPEP ? 1302.04(b).

2173.05(s)	Reference to Figures or Tables

Where possible, claims are to be complete in themselves. 
Incorporation by reference to a specific figure or table "is 
permitted only in exceptional circumstances where there is 
no practical way to define the invention in words and where 
it is more concise to incorporate by reference than duplicat-
ing a drawing or table into the claim. Incorporation by ref-
erence is a necessity doctrine, not for applicant's 
convenience." Ex parte Fressola, 27 USPQ2d 1608, 1609 
(Bd. Pat. App. & Inter. 1993) (citations omitted). 

Reference characters corresponding to elements recited 
in the detailed description and the drawings may be used in 
conjunction with the recitation of the same element or 
group of elements in the claims. See  MPEP ? 608.01(m).

2173.05(t)	Chemical Formula

Claims to chemical compounds and compositions con-
taining chemical compounds often use formulas that depict 
the chemical structure of the compound. These structures 
should not be considered indefinite nor speculative in the 
absence of evidence that the assigned formula is in error. 
The absence of corroborating spectroscopic or other data 
cannot be the basis for finding the structure indefinite. See 
Ex parte Morton, 134 USPQ 407 (Bd. App. 1961), and Ex 
parte Sobin, 139 USPQ 528 (Bd. App. 1962), in this 
regard.

A claim to a chemical compound is not indefinite merely 
because a structure is not presented or because a partial 
structure is presented. For example, the claim language at 
issue in In re Fisher, 427 F.2d 833, 166 USPQ 18 (CCPA 
1970) referred to a chemical compound as a "polypeptide 
of at least 24 amino acids having the following sequence." 
A rejection under 35 U.S.C. 112, second paragraph for fail-
ure to identify the entire structure was reversed and the 
court held: "While the absence of such a limitation obvi-
ously broadens the claim and raises questions of suffi-
ciency of disclosure, it does not render the claim 
indefinite." Chemical compounds may be claimed by a 
name that adequately describes the material to one skilled 
in the art. See Martin v. Johnson, 454 F.2d 746, 172 USPQ 
391 (CCPA 1972). A compound of unknown structure may 
be claimed by a combination of physical and chemical 
characteristics. See Ex parte Brian, 118 USPQ 242 (Bd. 
App. 1958). A compound may also be claimed in terms of 
the process by which it is made without raising an issue of 
indefiniteness. 

2173.05(u)	Trademarks or Trade Names in a 
Claim

The presence of a trademark or trade name in a claim is 
not, per se, improper under 35 U.S.C. 112, second para-
graph, but the claim should be carefully analyzed to deter-
mine how the mark or name is used in the claim. It is 
important to recognize that a trademark or trade name is 
used to identify a source of goods, and not the goods them-
selves. Thus a trademark or trade name does not identify or 
describe the goods associated with the trademark or trade 
name. See definitions of trademark and trade name in  
MPEP ? 608.01(v). A list of some trademarks is found in 
Appendix I.

If the trademark or trade name is used in a claim as a 
limitation to identify or describe a particular material or 
product, the claim does not comply with the requirements 
of the 35 U.S.C. 112, second paragraph. Ex parte Simpson, 
218 USPQ 1020 (Bd. App. 1982). The claim scope is 
uncertain since the trademark or trade name cannot be used 
properly to identify any particular material or product. In 
fact, the value of a trademark would be lost to the extent 
that it became descriptive of a product, rather than used as 
an identification of a source or origin of a product. Thus, 
the use of a trademark or trade name in a claim to identify 
or describe a material or product would not only render a 
claim indefinite, but would also constitute an improper use 
of the trademark or trade name.

If a trademark or trade name appears in a claim and is 
not intended as a limitation in the claim, the question of 
why it is in the claim should be addressed. Does its pres-
ence in the claim cause confusion as to the scope of the 
claim? If so, the claim should be rejected under 35 U.S.C. 
112, second paragraph.

2173.05(v)	Mere Function of Machine

In view of the decision of the Court of Customs and 
Patent Appeals in In re Tarczy-Hornoch, 397 F.2d 856, 158 
USPQ 141 (CCPA 1968), process or method claims are not 
subject to rejection by Patent and Trademark Office exam-
iners under  35 U.S.C. 112, second paragraph, solely on the 
ground that they define the inherent function of a disclosed 
machine or apparatus. The court in Tarczy-Hornoch held 
that a process claim, otherwise patentable, should not be 
rejected merely because the application of which it is part 
discloses apparatus which will inherently carry out the 
recited steps.

2173.06	Prior Art Rejection of Claim  
Rejected as Indefinite

All words in a claim must be considered in judging the 
patentability of a claim against the prior art. In re Wilson, 
424 F.2d 1382, 165 USPQ 494 (CCPA 1970). The fact that 
terms may be indefinite does not make the claim obvious 
over the prior art. When the terms of a claim are considered 
to be indefinite, at least two approaches to the examination 
of an indefinite claim relative to the prior art are possible.

First, where the degree of uncertainty is not great, and 
where the claim is subject to more than one interpretation 
and at least one interpretation would render the claim 
unpatentable over the prior art, an appropriate course of 
action would be for the examiner to enter two rejections: 
(A) a rejection based on indefiniteness under 35 U.S.C. 
112, second paragraph; and (B) a rejection over the prior art 
based on the interpretation of the claims which renders the 
prior art applicable. Ex parte Ionescu, 222 USPQ 537 (Bd. 
App. 1984). When making a rejection over prior art in these 
circumstances, it is important for the examiner to point out 
how the claim is being interpreted. Second, where there is a 
great deal of confusion and uncertainty as to the proper 
interpretation of the limitations of a claim, it would not be 
proper to reject such a claim on the basis of prior art. As 
stated in In re Steele, 305 F.2d 859, 134 USPQ 292 (CCPA 
1962), a rejection under 35 U.S.C. 103 should not be based 
on considerable speculation about the meaning of terms 
employed in a claim or assumptions that must be made as 
to the scope of the claims. 

The first approach is recommended from an examination 
standpoint because it avoids piecemeal examination in the 
event that the examiner's  35 U.S.C. 112, second paragraph 
rejection is not affirmed, and may give applicant a better 
appreciation for relevant prior art if the claims are redrafted 
to avoid the  35 U.S.C. 112, second paragraph rejection.

2174	Relationship Between the 
Requirements of the First and Second 
Paragraphs of 35 U.S.C. 112

The requirements of the first and second paragraphs of  
35 U.S.C. 112 are separate and distinct. If a description or 
the enabling disclosure of a specification is not commensu-
rate in scope with the subject matter encompassed by a 
claim, that fact alone does not render the claim imprecise or 
indefinite or otherwise not in compliance with 35 U.S.C. 
112, second paragraph; rather, the claim is based on an 
insufficient disclosure (35 U.S.C. 112, first paragraph) and 
should be rejected on that ground. In re Borkowski, 422 
F.2d 904, 164 USPQ 642 (CCPA 1970). If the specification 
discloses that a particular feature or element is critical or 
essential to the practice of the invention, failure to recite or 
include that particular feature or element in the claims may 
provide a basis for a rejection based on the ground that 
those claims are not supported by an enabling disclosure. In 
re Mayhew, 527 F.2d 1229, 188 USPQ 356 (CCPA 1976). 
In Mayhew, the examiner argued that the only mode of 
operation of the process disclosed in the specification 
involved the use of a cooling zone at a particular location in 
the processing cycle. The claims were rejected because 
they failed to specify either a cooling step or the location of 
the step in the process. The court was convinced that the 
cooling bath and its location were essential, and held that 
claims which failed to recite the use of a cooling zone, spe-
cifically located, were not supported by an enabling disclo-
sure (35 U.S.C. 112, first paragraph).

In addition, if a claim is amended to include an invention 
that is not described in the application as filed, a rejection 
of that claim under  35 U.S.C. 112, first paragraph as being 
directed to subject matter that is not described in the speci-
fication as filed may be appropriate.   In re Simon, 302 F.2d 
737, 133 USPQ 524 (CCPA 1962); In re Panagrossi, 277 
F.2d 181, 125 USPQ 410 (CCPA 1960). In Simon, which 
involved a reissue application containing claims to a reac-
tion product of a composition, applicant presented claims to 
a reaction product of a composition comprising the sub-
combination A+B+C, whereas the original claims and 
description of the invention were directed to a composition 
comprising the combination A+B+C+D+E. The court 
found no significant support for the argument that ingredi-
ents D+E were not essential to the claimed reaction product 
and concluded that claims directed to the reaction product 
of a subcombination A+B+C were not described (35 U.S.C. 
112, first paragraph) in the application as filed.

2181	Identifying a 35 U.S.C. 112, Sixth  
Paragraph Limitation [R-1]

The purpose of this section is to set forth guidelines for 
the examination of 35 U.S.C. 112, sixth paragraph "means 
or step plus function" limitations in a claim. The Court of 
Appeals for the Federal Circuit, in its en banc decision In re 
Donaldson Co., 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 
1994), decided that a "means-or-step-plus-function" limita-
tion should be interpreted in a manner different than patent 
examining practice had previously dictated. The Donaldson 
decision affects only the manner in which the scope of a 
"means or step plus function" limitation in accordance with  
35 U.S.C. 112, sixth paragraph, is interpreted during exam-
ination.   Donaldson does not directly affect the manner in 
which any other section of the patent statutes is interpreted 
or applied.

When making a determination of patentability under 
35 U.S.C. 102 or 103, past practice was to interpret a 
"means or step plus function" limitation by giving it the 
"broadest reasonable interpretation." Under the PTO's 
long-standing practice this meant interpreting such a limita-
tion as reading on any prior art means or step which per-
formed the function specified in the claim without regard 
for whether the prior art means or step was equivalent to 
the corresponding structure, material or acts described in 
the specification. However, in Donaldson, the Federal Cir-
cuit stated:

Per our holding, the "broadest reasonable interpretation" that an 
examiner may give means-plus-function language is that statuto-
rily mandated in paragraph six. Accordingly, the PTO may not 
disregard the structure disclosed in the specification correspond-
ing to such language when rendering a patentability determina-
tion. 

LANGUAGE FALLING WITHIN 35 U.S.C. 112, 
SIXTH PARAGRAPH

** >The PTO must apply 35 U.S.C. 112, sixth paragraph 
in appropriate cases, and give claims their broadest reason-
able interpretation, in light of and consistent with the writ-
ten description of the invention in the application. See 
Donaldson, 16 F.3d at 1194, 29 USPQ2d at 1850 (stating 
that 35 U.S.C. 112, sixth paragraph "merely sets a limit on 
how broadly the PTO may construe means-plus-function 
language under the rubric of `reasonable interpretation.' "). 
The Federal Circuit has held that applicants (and reexami-
nation patentees) before the PTO have the opportunity and 
the obligation to define their inventions precisely during 
proceedings before the PTO. See In re Morris, 127 F.3d 
1048, 1056-57, 44 USPQ2d 1023, 1029-30 (Fed. Cir. 
1997) (35 U.S.C. 112, second paragraph places the burden 
of precise claim drafting on the applicant); In re Zletz, 893 
F.2d 319, 322, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) 
(manner of claim interpretation that is used by courts in lit-
igation is not the manner of claim interpretation that is 
applicable during prosecution of a pending application 
before the PTO). Applicants and reexamination patentees 
before the PTO have an opportunity and obligation to spec-
ify, consistent with these guidelines, when a claim limita-
tion invokes 35 U.S.C. 112, sixth paragraph.

 A claim limitation will be interpreted to invoke 
35 U.S.C. 112, sixth paragraph if it meets the following 3-
prong analysis: 

(A)	 the claim limitations must use the phrase "means 
for" or "step for";

(B)	 the "means for" or "step for" must be modified by 
functional language; and

(C)	 the phrase "means for" or "step for" must not be 
modified by structure, material or acts for achieving the 
specified function.

 With respect to the first prong of this analysis, a claim 
element that does not include the phrase "means for" or 
"step for" will not be considered to invoke 35 U.S.C. 112, 
sixth paragraph. If an applicant wishes to have the claim 
limitation treated under 35 U.S.C. 112, sixth paragraph, 
applicant must either: (A) amend the claim to include the 
phrase "means for" or "step for" in accordance with these 
guidelines; or (B) show that even though the phrase "means 
for" or "step for" is not used, the claim limitation is written 
as a function to be performed and does not provide any 
structure, material, or acts which would preclude applica-
tion of 35 U.S.C.  112, sixth paragraph. While traditional 
"means for" or "step for" language does not automatically 
make an element a means-(or step-) plus-function element, 
conversely, lack of such language does not prevent a limita-
tion from being construed as a means-(or step-) plus-func-
tion limitation. See Signtech USA, Ltd. v. Vutek, Inc., 174 
F.3d 1352, 1356, 50 USPQ2d 1372, 1374-75 (Fed. Cir. 
1999) ("ink delivery means positioned on ?" invokes 
35 U.S.C. 112, sixth paragraph since the phrase "ink deliv-
ery means" is equivalent to "means for ink delivery"); Seal-
Flex, Inc.  v. Athletic Track and Court Construction, 172 
F.3d 836, 850, 50 USPQ2d 1225, 1234 (Fed. Cir. 1999) 
(Radar, J., concurring) ("claim elements without express 
step-plus-function language may nevertheless fall within 
112 ? 6 if they merely claim the underlying function with-
out recitation of acts for performing that function?In gen-
eral terms, the `underlying function' of a method claim 
element corresponds to what that element ultimately 
accomplishes in relationship to what the other elements of 
the claim and the claim as a whole accomplish. `Acts,'  on 
the other hand, correspond to how the function is accom-
plished?If the claim element uses the phrase `step for,' 
then ? 112, ? 6 is presumed to apply?On the other hand, 
the term `step' alone and the phrase `steps of' tend to show 
that ? 112, ? 6 does not govern that limitation."); Personal-
ized Media Communications LLC v. ITC, 161 F.3d 696, 
703-04, 48 USPQ2d 1880, 1886-87 (Fed. Cir. 1998); Mas-
Hamilton Group v. LaGard Inc., 156 F.3d 1206, 1213, 48 
USPQ2d 1010, 1016 (Fed. Cir. 1998) ("lever moving ele-
ment for moving the lever" and "movable link member for 
holding the lever?and for releasing the lever" were con-
strued as means-plus-function limitations invoking 
35 U.S.C. 112, sixth paragraph since the claimed limita-
tions were described in terms of their function not their 
mechanical structure); Ethicon, Inc. v. United States Surgi-
cal Corp., 135 F.3d 1456, 1463, 45 USPQ2d 1545, 1550 
(Fed. Cir. 1998) ("use of the word `means' gives rise to `a 
presumption that the inventor used the term advisedly to 
invoke the statutory mandates for means-plus-function 
clauses' "); O.I. Corp. v. Tekmar, 115 F.3d 1576, 1583, 42 
USPQ2d 1777, 1782 (Fed. Cir. 1997) (method claim that 
paralleled means-plus-function apparatus claim but lacked 
"step for" language did not invoke 35 U.S.C. 112, sixth 
paragraph). Thus, absent an express recitation of  "means 
for" or "step for" in the limitation, the broadest reasonable 
interpretation will not be limited to "corresponding struc-
ture?and equivalents thereof." Morris, 127 F.3d at 1055, 
44 USPQ2d at 1028 ("no comparable mandate in the patent 
statute that relates the claim scope of non-? 112 ? 6 claims 
to particular matter found in the specification"). 

With respect to the second prong of this analysis, see 
York Prod., Inc. v. Central Tractor Farm & Family Center, 
99 F.3d 1568, 1574, 40 USPQ2d 1619, 1624 (Fed. Cir. 
1996) (holding that a claim limitation containing the term 
"means" does not invoke 35 U.S.C. 112, sixth paragraph if 
the claim limitation does not link the term "means" to a 
specific function). It must be clear that the element in the 
claims is set forth, at least in part, by the function it per-
forms as opposed to the specific structure, material, or acts 
that perform the function. See also Caterpillar Inc. v. 
Detroit Diesel Corp., 41 USPQ2d 1876, 1882 (N.D. Ind. 
1996) (35 U.S.C. 112, sixth paragraph "applies to func-
tional method claims where the element at issue sets forth a 
step for reaching a particular result, but not the specific 
technique or procedure used to achieve the result.");O.I. 
Corp., 115 F.3d at 1582-83, 42 USPQ2d at 1782 (With 
respect to process claims, "[35 U.S.C. 112, sixth paragraph] 
is implicated only when steps plus function without acts are 
present?If we were to construe every process claim con-
taining steps described by an `ing' verb, such as passing, 
heating, reacting, transferring, etc., into a step-plus-func-
tion, we would be limiting process claims in a manner 
never intended by Congress." (Emphasis in original).). 
However, "the fact that a particular mechanism?is defined 
in functional terms is not sufficient to convert a claim ele-
ment containing that term into a `means for performing a 
specified function' within the meaning of section 112(6)." 
Greenberg v. Ethicon Endo-Surgery, Inc., 91 F.3d 1580, 
1583, 39 USPQ2d 1783, 1786 (Fed. Cir. 1996) ("detent 
mechanism" defined in functional terms was not intended 
to invoke 35 U.S.C. 112, sixth paragraph). See also Al-Site 
Corp. v. VSI International Inc., 174 F.3d 1308, 1318, 50 
USPQ2d 1161, 1166-67 (Fed. Cir. 1999) (although the 
claim elements "eyeglass hanger member" and "eyeglass 
contacting member" include a function, these claim ele-
ments do not invoke 35 U.S.C. 112, sixth paragraph 
because the claims themselves contain sufficient structural 
limitations for performing those functions). Also, a state-
ment of function appearing only in the claim preamble is 
generally insufficient to invoke 35 U.S.C. 112, sixth para-
graph. O.I. Corp., 115 F.3d at 1583, 42 USPQ2d at 1782 
("[A] statement in a preamble of a result that necessarily 
follows from performing a series of steps does not convert 
each of those steps into step- plus-function clauses. The 
steps of `passing'  are not individually associated in the 
claims with functions performed by the steps of passing."). 

With respect to the third prong of this analysis, see Seal-
Flex, 172 F.3d at 849, 50 USPQ2d at 1234 (Radar, J., con-
curring) ("Even when a claim element uses language that 
generally falls under the step-plus-function format, how-
ever, 112 ? 6 still does not apply when the claim limitation 
itself recites sufficient acts for performing the specified 
function."); Rodime PLC v. Seagate Technology, Inc., 174 
F.3d 1294, 1303- 04, 50 USPQ2d 1429, 1435-36 (Fed. Cir. 
1999) (holding "positioning means for moving" does not 
invoke 35 U.S.C. 112, sixth paragraph because the claim 
further provides a list of the structure underlying the means 
and the detailed recitation of the structure for performing 
the moving function removes this element from the pur-
view of 35 U.S.C. 112, sixth paragraph); Cole v. Kimberly-
Clark Corp., 102 F.3d 524, 531, 41 USPQ2d 1001, 1006 
(Fed. Cir. 1996) (holding "perforation means?for tearing" 
does not invoke 35 U.S.C. 112, sixth paragraph because the 
claim describes the structure supporting the tearing func-
tion (i.e., perforation)). In other cases, the Federal Circuit 
has held otherwise. See Unidynamics Corp. v. Automatic 
Prod. Int'l, 157 F.3d 1311, 1319, 48 USPQ2d 1099, 1104 
(Fed. Cir. 1998) (holding "spring means" does invoke 
35 U.S.C. 112, sixth paragraph). Although use of the term 
"means" in a clause reciting predominantly structure does 
not evoke 35 U.S.C. 112, sixth paragraph, York Products, 
99 F.3d at 1574, 40 USPQ2d at 1623, "[t]he recitation of 
some structure in a means plus function element does not 
preclude applicability of section 112(6)." During examina-
tion, however, applicants have the opportunity and the obli-
gation to define their inventions precisely, including 
whether a claim limitation invokes 35 U.S.C. 112, sixth 
paragraph. Thus, if the phrase "means for" or "step for" is 
modified by structure, material or acts for achieving the 
specified function, the PTO will not apply 35 U.S.C. 112, 
sixth paragraph until such modifying language is deleted 
from the claim limitation. Laitram Corp. v. Rexnord, Inc., 
939 F.2d 1533, 1536, 19 USPQ2d 1367, 1369 (Fed. Cir. 
1991). It is necessary to decide on an element by element 
basis whether 35 U.S.C. 112, sixth paragraph applies. Each 
claim must be independently reviewed to determine the 
applicability of 35 U.S.C. 112, sixth paragraph, even where 
the application contains substantially similar process and 
apparatus claims. O.I. Corp., 115 F.3d at 1583-1584, 42 
USPQ2d at 1782 ("We understand that the steps in the 
method claims are essentially in the same language as the 
limitations in the apparatus claim, albeit without the `means 
for' qualification?Each claim must be independently 
reviewed in order to determine if it is subject to the require-
ments of section 112, ? 6. Interpretation of claims would be 
confusing indeed if claims that are not means- or step- plus 
function were to be interpreted as if they were, only 
because they use language similar to that used in other 
claims that are subject to this provision.").

Accordingly, these guidelines provide applicants with 
the opportunity to either invoke or not invoke 35 U.S.C.  
112, sixth paragraph based upon a clear and simple set of 
criteria.<

Limitations that fall within the scope of 35 U.S.C. 112, 
sixth paragraph include:

(A)	a jet driving device so constructed and located on 
the rotor as to drive the rotor . . . ["means" unnecessary]. 
The term "device" coupled with a function is a proper defi-
nition of structure in accordance with the last paragraph of  
35 U.S.C. 112. The addition of the words "jet driving" to 
the term "device" merely renders the latter more definite 
and specific. Ex parte Stanley, 121 USPQ 621 (Bd. App. 
1958);

(B)	"printing means" and "means for printing" which 
would have the same connotations. Ex parte Klumb, 159 
USPQ 694 (Bd. App. 1967). However, the terms "plate" 
and "wing," as modifiers for the structureless term 
"means," specify no function to be performed, and do not 
fall under the last paragraph of  35 U.S.C. 112;

(C)	force generating means adapted to provide . . . .   
De Graffenreid v. United States, 20 Ct. Cl. 458, 16 USPQ2d 
1321 (Ct. Cl. 1990);

(D)	call cost register means, including a digital display 
for providing a substantially instantaneous display for . . . . 
Intellicall Inc. v. Phonometrics, Inc., 952 F.2d 1384, 21 
USPQ2d 1383 (Fed. Cir. 1992);

(E)	reducing the coefficient of friction of the resulting 
film [step plus function; "step" unnecessary], In re Roberts, 
470 F.2d 1399, 176 USPQ 313 (CCPA 1973); and

(F)	raising the pH of the resultant pulp to about 5.0 to 
precipitate . . . . Ex parte Zimmerley, 153 USPQ 367 (Bd. 
App. 1966).

In the event that it is unclear whether the claim limitation 
falls within the scope of  35 U.S.C. 112, sixth paragraph, a 
rejection under  35 U.S.C. 112, second paragraph may be 
appropriate.

>PROCEDURES FOR DETERMINING WHETHER 
THE WRITTEN DESCRIPTION ADEQUATELY 
DESCRIBES THE CORRESPONDING STRUCTURE, 
MATERIAL, OR ACTS NECESSARY TO SUPPORT 
A CLAIM LIMITATION WHICH INVOKES 35 U.S.C. 
112, SIXTH PARAGRAPH

If a claim limitation invokes 35 U.S.C. 112, sixth para-
graph, it must be interpreted to cover the corresponding 
structure, materials, or acts in the specification and "equiv-
alents thereof." See 35 U.S.C. 112, sixth paragraph. See 
also B. Braun Medical, Inc. v. Abbott Lab., 124 F.3d 1419, 
1424, 43 USPQ2d 1896, 1899 (Fed. Cir. 1997). If the writ-
ten description fails to set forth the supporting structure, 
material or acts corresponding to the means- (or step-) plus-
function, the claim may not meet the requirement of 35 
U.S.C.  112, second paragraph: 

Although [35 U.S.C. 112, sixth paragraph] statutorily provides 
that one may use means-plus- function language in a claim, one is 
still subject to the requirement that a claim `particularly point out 
and distinctly claim' the invention. Therefore, if one employs 
means-plus-function language in a claim, one must set forth in 
the specification an adequate disclosure showing what is meant 
by that language. If an applicant fails to set forth an adequate dis-
closure, the applicant has in effect failed to particularly point out 
and distinctly claim the invention as required by [35 U.S.C. 112, 
second paragraph].

See Donaldson, 16 F.3d at 1195, 29 USPQ2d at 1850; see 
also B. Braun Medical, 124 F.3d at 1425, 43 USPQ2d at 
1900; and In re Dossel, 115 F.3d 942, 946, 42 USPQ2d 
1881, 1884-85 (Fed. Cir. 1997). 

Whether a claim reciting an element in means- (or step-) 
plus-function language fails to comply with 35 U.S.C. 112, 
second paragraph because the specification does not dis-
close adequate structure (or material or acts) for performing 
the recited function is closely related to the question of 
whether the specification meets the description requirement 
in 35 U.S.C. 112, first paragraph. See In re Noll, 545 F.2d 
141, 149, 191 USPQ 721, 727 (CCPA 1976) (unless the 
means-plus-function language is itself unclear, a claim lim-
itation written in means-plus- function language meets the 
definiteness requirement in 35 U.S.C. 112, second para-
graph so long as the specification meets the written descrip-
tion requirement in 35 U.S.C. 112, first paragraph). 
However, 35 U.S.C. 112, sixth paragraph does not impose 
any requirements in addition to those imposed by 35 U.S.C.  
112, first paragraph. See In re Knowlton, 481 F.2d 1357, 
1366, 178 USPQ 486, 492-93 (CCPA 1973). Conversely, 
the invocation of 35 U.S.C. 112, sixth paragraph does not 
exempt an applicant from compliance with 35 U.S.C. 112, 
first and second paragraphs. See Donaldson, 16 F.3d at 
1195, 29 USPQ2d at 1850; Knowlton, 481 F.2d at 1366, 
178 USPQ at 493. 

The written description does not have to explicitly 
describe the structure (or material or acts) corresponding to 
a means- (or step-) plus-function limitation to particularly 
point out and distinctly claim the invention as required by 
35 U.S.C.  112, second paragraph. See Dossel, 115 F.3d at 
946, 42 USPQ2d at 1885. Under proper circumstances, 
drawings may provide a written description of an invention 
as required by 35 U.S.C. 112. Vas-Cath, Inc. v. Mahurkar, 
935 F.2d 1555, 1565, 19 USPQ2d 1111, 1118 (Fed. Cir. 
1991). Rather, disclosure of structure corresponding to 
a means-plus-function limitation may be implicit in the 
written description if it would have been clear to those 
skilled in the art what structure must perform the function 
recited in the means-plus-function limitation. See Atmel 
Corp. v. Information Storage Devices Inc., 198 F.3d 1374, 
___, 53 USPQ2d 1225, 1229 (Fed. Cir. 1999); Dossel, 115 
F.3d at 946-47, 42 USPQ2d at 1885 ("Clearly, a unit which 
receives digital data, performs complex mathematical com-
putations and outputs the results to a display must be imple-
mented by or on a general or special purpose computer 
(although it is not clear why the written description does 
not simply state `computer' or some equivalent phrase.)"). 
However, the claims must still be analyzed to determine 
whether there exists corresponding adequate support for 
such claim under 35 U.S.C. 112, first paragraph. In consid-
ering whether there is 35 U.S.C. 112, first paragraph sup-
port for the claim limitation, the examiner must consider 
not only the original disclosure contained in the summary 
and detailed description of the invention portions of the 
specification, but also the original claims, abstract, and 
drawings. See In re Mott, 539 F.2d 1291, 1299, 190 USPQ 
536, 542-43 (CCPA 1976) (claims); In re Anderson, 471 
F.2d 1237, 1240, 176 USPQ 331, 333 (CCPA 1973) 
(claims); In re Armbruster, 512 F.2d 676, 678-79, 185 
USPQ 152, 153-54 (CCPA 1975) (abstract); Anderson, 471 
F.2d at 1240, 176 USPQ at 333 (abstract); Vas-Cath Inc. v. 
Mahurkar, 935 F.2d at 1564, 19 USPQ2d at 1117 (draw-
ings); In re Wolfensperger, 302 F.2d 950, 955-57, 133 
USPQ 537, 541- 43 (CCPA 1962) (drawings). 

Therefore, a means-(or step-) plus-function claim limita-
tion satisfies 35 U.S.C. 112, second paragraph if: (A) the 
written description links or associates particular structure, 
materials, or acts to the function recited in a means- (or 
step-) plus-function claim limitation; or (B) it is clear based 
on the facts of the application that one skilled in the art 
would have known what structure, materials, or acts per-
form the function recited in a means- (or step-) plus-func-
tion limitation. 

37 CFR  1.75(d)(1) provides, in part, that "the terms and 
phrases used in the claims must find clear support or ante-
cedent basis in the description so that the meaning of the 
terms in the claims may be ascertainable by reference to the 
description." In the situation in which the written descrip-
tion only implicitly or inherently sets forth the structure, 
materials, or acts corresponding to a means- (or step-) plus-
function, and the examiner concludes that one skilled in the 
art would recognize what structure, materials, or acts per-
form the function recited in a means- (or step-) plus-func-
tion, the examiner should either: (A) have the applicant 
clarify the record by amending the written description such 
that it expressly recites what structure, materials, or acts 
perform the function recited in the claim element; or (B) 
state on the record what structure, materials, or acts per-
form the function recited in the means- (or step-) plus-func-
tion limitation. Even if the disclosure implicitly sets forth 
the structure, materials, or acts corresponding to a means- 
(or step-) plus-function claim element in compliance with 
35 U.S.C. 112, first and second paragraphs, the PTO may 
still require the applicant to amend the specification pursu-
ant to 37 CFR  1.75(d) and MPEP ?  608.01(o) to explicitly 
state, with reference to the terms and phrases of the claim 
element, what structure, materials, or acts perform the func-
tion recited in the claim element. See 35 U.S.C. 112, sixth 
paragraph ("An element in a claim for a combination may 
be expressed as a means or step for performing a specified 
function without the recital of structure, material, or acts in 
support thereof, and such claim shall be construed to cover 
the corresponding structure, material, or acts described in 
the specification and equivalents thereof." (emphasis 
added)); see also B. Braun Medical, 124 F.3d at 1424, 43 
USPQ2d at 1900 (holding that "pursuant to this provision 
[35 U.S.C.  112, sixth paragraph], structure disclosed in the 
specification is `corresponding' structure only if the speci-
fication or prosecution history clearly links or associates 
that structure to the function recited in the claim. This duty 
to link or associate structure to function is the quid pro quo 
for the convenience of employing 112, paragraph 6."); 
Wolfensperger, 302 F.2d at 955, 133 USPQ at 542 (just 
because the disclosure provides support for a claim element 
does not mean that the PTO cannot enforce its requirement 
that the terms and phrases used in the claims find clear sup-
port or antecedent basis in the written description).<

SINGLE MEANS CLAIMS

Donaldson does not affect the holding of In re Hyatt, 
708 F.2d 712, 218 USPQ 195 (Fed. Cir. 1983) to the effect 
that a single means claim does not comply with the enable-
ment requirement of 35 U.S.C. 112, first paragraph. As 
Donaldson applies only to an interpretation of a limitation 
drafted to correspond to 35 U.S.C. 112, sixth paragraph, 
which by its terms is limited to "an element in a claim to a 
combination," it does not affect a limitation in a claim 
which is not directed to a combination.

2182	Scope of the Search and Identification 
of the Prior Art

As noted in  MPEP ? 2181, in In re Donaldson Co., 16 
F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994) the Federal 
Circuit recognized that it is important to retain the principle 
that claim language should be given its broadest reasonable 
interpretation. This principle is important because it helps 
insure that the statutory presumption of validity attributed 
to each claim of an issued patent is warranted by the search 
and examination conducted by the examiner. It is also 
important from the standpoint that the scope of protection 
afforded by patents issued prior to Donaldson are not 
unnecessarily limited by the latest interpretation of this 
statutory provision. Finally, it is important from the stand-
point of avoiding the necessity for a patent specification to 
become a catalogue of existing technology. A patent speci-
fication need not teach, and preferably omits, what is well 
known in the art. Hybritech Inc. v. Monoclonal Antibodies, 
Inc., 802 F.2d 1367, 1384, 231 USPQ 81, 94 (Fed. Cir. 
1986).

The Donaldson decision thus does not substantially alter 
examining practice and procedure relative to the scope of 
the search. Both before and after Donaldson, the applica-
tion of a prior art reference to a means or step plus function 
limitation requires that the prior art element perform the 
identical function specified in the claim. However, if a prior 
art reference teaches identity of function to that specified in 
a claim, then under   Donaldson an examiner carries the ini-
tial burden of proof for showing that the prior art structure 
or step is the same as or equivalent to the structure, mate-
rial, or acts described in the specification which has been 
identified as corresponding to the claimed means or step 
plus function.

The "means or step plus function" limitation should be 
interpreted in a manner consistent with the specification 
disclosure. If the specification defines what is meant by the 
limitation for the purposes of the claimed invention, the 
examiner should interpret the limitation as having that 
meaning. If no definition is provided, some judgment must 
be exercised in determining the scope of the limitation.  
See, e.g., B. Braun Medical, Inc. v. Abbott Labs., 124 F.3d 
1419, 1424, 43 USPQ2d 1896, 1900 (Fed. Cir. 1997) ("We 
hold that, pursuant to [35 U.S.C. 112, sixth paragraph], 
structure disclosed in the specification is `corresponding' 
structure only if the specification or prosecution history 
clearly links or associates that structure to the function 
recited in the claim.  This duty to link or associate structure 
to function is the quid pro quo for the convenience of 
employing 112, paragraph 6." The court refused to interpret 
a means-plus-function limitation as corresponding to a dis-
closed valve seat structure, as argued by patentee, since 
there was no indication in the specification or prosecution 
history that this structure corresponds to the recited func-
tion, and there was an explicitly clear association between 
that function and a traverse cross section bar structure dis-
closed in the specification.).

2183	Making a Prima Facie Case of   
Equivalence

If the examiner finds that a prior art element performs 
the function specified in the claim, and is not excluded by 
any explicit definition provided in the specification for an 
equivalent, the examiner should infer from that finding that 
the prior art element is an equivalent, and should then con-
clude that the claimed limitation is anticipated by the prior 
art element. The burden then shifts to applicant to show 
that the element shown in the prior art is not an equivalent 
of the structure, material or acts disclosed in the applica-
tion. In re Mulder, 716 F.2d 1542, 219 USPQ 189 (Fed. Cir. 
1983). No further analysis of equivalents is required of the 
examiner until applicant disagrees with the examiner's con-
clusion, and provides reasons why the prior art element 
should not be considered an equivalent. See also, In re 
Walter, 618 F.2d 758, 768, 205 USPQ 397, 407-08 (CCPA 
1980) (a case treating  35 U.S.C. 112, sixth paragraph, in 
the context of a determination of statutory subject matter 
and noting "If the functionally-defined disclosed means 
and their equivalents are so broad that they encompass any 
and every means for performing the recited functions . . . 
the burden must be placed on the applicant to demonstrate 
that the claims are truly drawn to specific apparatus distinct 
from other apparatus capable of performing the identical 
functions"); In re Swinehart, 439 F.2d 210, 212-13, 169 
USPQ 226, 229 (CCPA 1971) (a case in which the court 
treated as improper a rejection under 35 U.S.C. 112, second 
paragraph, of functional language, but noted that "where 
the Patent Office has reason to believe that a functional 
limitation asserted to be critical for establishing novelty in 
the claimed subject matter may, in fact, be an inherent char-
acteristic of the prior art, it possesses the authority to 
require the applicant to prove that the subject matter shown 
to be in the prior art does not possess the characteristics 
relied on"); and In re Fitzgerald, 619 F.2d 67, 205 USPQ 
594 (CCPA 1980) (a case indicating that the burden of 
proof can be shifted to the applicant to show that the sub-
ject matter of the prior art does not possess the characteris-
tic relied on whether the rejection is based on inherency 
under  35 U.S.C. 102 or obviousness under 35 U.S.C. 103).

See  MPEP ? 2184 for the factors to be considered when 
determining whether the applicant has successfully met the 
burden of proving that the prior art element is not equiva-
lent to the structure, material or acts described in the appli-
cant's specification.

IF NONEQUIVALENCE SHOWN, EXAMINER 
MUST CONSIDER OBVIOUSNESS 

However, even where the applicant has met that burden 
of proof and has shown that the prior art element is not 
equivalent to the structure, material or acts described in the 
applicant's specification, the examiner must still make a 
35 U.S.C. 103 analysis to determine if the claimed means 
or step plus function is obvious from the prior art to one of 
ordinary skill in the art. Thus, while a finding of nonequiv-
alence prevents a prior art element from anticipating a 
means or step plus function limitation in a claim, it does not 
prevent the prior art element from rendering the claim limi-
tation obvious to one of ordinary skill in the art. Because 
the exact scope of an "equivalent" may be uncertain, it 
would be appropriate to apply a 35 U.S.C. 102/103 rejec-
tion where the balance of the claim limitations are antici-
pated by the prior art relied on. A similar approach is 
authorized in the case of product-by-process claims 
because the exact identity of the claimed product or the 
prior art product cannot be determined by the examiner. In 
re Brown, 450 F.2d 531, 173 USPQ 685 (CCPA 1972). In 
addition, although it is normally the best practice to rely on 
only the best prior art references in rejecting a claim, alter-
native grounds of rejection may be appropriate where the 
prior art shows elements that are different from each other, 
and different from the specific structure, material or acts 
described in the specification, yet perform the function 
specified in the claim.

2184	Determining Whether an Applicant  
Has Met the Burden of Proving  
Nonequivalence After a Prima Facie 
Case Is Made

If the applicant disagrees with the inference of equiva-
lence drawn from a prior art reference, the applicant may 
provide reasons why the applicant believes the prior art ele-
ment should not be considered an equivalent to the specific 
structure, material or acts disclosed in the specification. 
Such reasons may include, but are not limited to: 

(A)	Teachings in the specification that particular prior 
art is not equivalent; 

(B)	Teachings in the prior art reference itself that may 
tend to show nonequivalence; or 

(C)	37 CFR 1.132 affidavit evidence of facts tending 
to show nonequivalence.

TEACHINGS IN APPLICANT'S SPECIFICATION

When the applicant relies on teachings in applicant's 
own specification, the examiner must make sure that the 
applicant is interpreting the "means or step plus function" 
limitation in the claim in a manner which is consistent with 
the disclosure in the specification. If the specification 
defines what is meant by "equivalents" to the disclosed 
embodiments for the purpose of the claimed means or step 
plus function, the examiner should interpret the limitation 
as having that meaning. If no definition is provided, some 
judgment must be exercised in determining the scope of 
"equivalents." Generally, an "equivalent" is interpreted as 
embracing more than the specific elements described in the 
specification for performing the specified function, but less 
than any element that performs the function specified in the 
claim. To interpret "means plus function" limitations as 
limited to a particular means set forth in the specification 
would nullify the provisions of 35 U.S.C. 112 requiring that 
the limitation shall be construed to cover the structure 
described in the specification and equivalents thereof. 
D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1574, 225 
USPQ 236, 238 (Fed. Cir. 1985).

The scope of equivalents embraced by a claim limitation 
is dependent on the interpretation of an "equivalent." The 
interpretation will vary depending on how the element is 
described in the supporting specification. The claim may or 
may not be limited to particular structure, material or acts 
(e.g., steps) as opposed to any and all structure, material or 
acts performing the claimed function, depending on how 
the specification treats that question. 

If the disclosure is so broad as to encompass any and all 
structure, material or acts for performing the claimed func-
tion, the claims must be read accordingly when determining 
patentability. When this happens the limitation otherwise 
provided by "equivalents" ceases to be a limitation on the 
scope of the claim in that an equivalent would be any struc-
ture, material or act other than the ones described in the 
specification that perform the claimed function. For exam-
ple, this situation will often be found in cases where (A) the 
claimed invention is a combination of elements, one or 
more of which are selected from elements that are old, per 
se, or (B) apparatus claims are treated as indistinguishable 
from method claims. See, for example, In re Meyer, 688 
F.2d 789, 215 USPQ 193 (CCPA 1982); In re Abele, 684 
F.2d 902, 909, 214 USPQ 682, 688 (CCPA 1982); In re 
Walter, 618 F.2d 758, 767, 205 USPQ 397, 406-07 (CCPA 
1980); In re Maucorps, 609 F.2d 481, 203 USPQ 812 
(CCPA 1979); In re Johnson, 589 F.2d 1070, 200 USPQ 
199 (CCPA 1978); and In re Freeman, 573 F.2d 1237, 
1246, 197 USPQ 464, 471 (CCPA 1978). 

On the other end of the spectrum, the "equivalents" limi-
tation as applied to a claim may also operate to constrict the 
claim scope to the point of covering virtually only the dis-
closed embodiments. This can happen in circumstances 
where the specification describes the invention only in the 
context of a specific structure, material or act that is used to 
perform the function specified in the claim.

FACTORS TO BE CONSIDERED IN DECIDING 
EQUIVALENCE

When deciding whether an applicant has met the burden 
of proof with respect to showing nonequivalence of a prior 
art element that performs the claimed function, the follow-
ing factors may be considered. First, unless an element per-
forms the identical function specified in the claim, it cannot 
be an equivalent for the purposes of  35 U.S.C. 112, sixth 
paragraph. Pennwalt Corp. v. Durand-Wayland, Inc., 833 
F.2d 931, 4 USPQ2d 1737 (Fed. Cir. 1987), cert. denied, 
484 U.S. 961 (1988).

Second, while there is no litmus test for an "equivalent" 
that can be applied with absolute certainty and predictabil-
ity, there are several indicia that are sufficient to support a 
conclusion that one element is or is not an "equivalent" of a 
different element in the context of 35 U.S.C. 112, sixth 
paragraph. Among the indicia that will support a conclu-
sion that one element is or is not an equivalent of another 
are:

(A)	Whether the prior art element performs the func-
tion specified in the claim in substantially the same way, 
and produces substantially the same results as the corre-
sponding element disclosed in the specification. Lockheed 
Aircraft Corp. v. United States, 193 USPQ 449, 461 (Ct. Cl. 
1977). The concepts of equivalents as set forth in Graver 
Tank & Mfg. Co. v. Linde Air Products, 339 U.S. 605, 85 
USPQ 328 (1950) are relevant to any "equivalents" deter-
mination. Polumbo v. Don-Joy Co., 762 F.2d 969, 975, n. 4, 
226 USPQ 5, 8-9, n. 4 (Fed. Cir. 1985).

(B)	Whether a person of ordinary skill in the art would 
have recognized the interchangeability of the element 
shown in the prior art for the corresponding element dis-
closed in the specification. Lockheed Aircraft Corp. v. 
United States, 193 USPQ 449, 461 (Ct. Cl. 1977); Data 
Line Corp. v. Micro Technologies, Inc., 813 F.2d 1196, 1 
USPQ2d 2052 (Fed. Cir. 1987).

(C)	Whether the prior art element is a structural equiv-
alent of the corresponding element disclosed in the specifi-
cation being examined. In re Bond, 910 F.2d 831, 15 
USPQ2d 1566 (Fed. Cir. 1990). That is, the prior art ele-
ment performs the function specified in the claim in sub-
stantially the same manner as the function is performed by 
the corresponding element described in the specification.

(D)	Whether there are insubstantial differences 
between the prior art element and the structure, material or 
acts disclosed in the specification. Warner-Jenkinson Co. v. 
Hilton Davis Chemical Co., 117 S. Ct. 1040, 41 USPQ2d 
1865, 1875 (1997);   Valmont Industries, Inc. v. Reinke Mfg. 
Co., 983 F.2d 1039, 25 USPQ2d 1451 (Fed. Cir. 1993). 

These examples are not intended to be an exhaustive list 
of the indicia that would support a finding that one element 
is or is not an equivalent of another element for the pur-
poses of  35 U.S.C. 112, sixth paragraph. A finding accord-
ing to any of the above examples would represent a 
sufficient, but not the only possible, basis to support a con-
clusion that an element is or is not an equivalent. There 
could be other indicia that also would support the conclu-
sion.

MERE ALLEGATIONS OF NONEQUIVALENCE 
ARE NOT SUFFICIENT 

In determining whether arguments or 37 CFR 1.132 evi-
dence presented by an applicant are persuasive that the ele-
ment shown in the prior art is not an equivalent, the 
examiner should consider and weigh as many of the above-
indicated or other indicia as are presented by applicant, and 
should determine whether, on balance, the applicant has 
met the burden of proof to show nonequivalence. However, 
under no circumstance should an examiner accept as per-
suasive a bare statement or opinion that the element shown 
in the prior art is not an equivalent embraced by the claim 
limitation. Moreover, if an applicant argues that the 
"means" or "step" plus function language in a claim is lim-
ited to certain specific structural or additional functional 
characteristics (as opposed to "equivalents" thereof) where 
the specification does not describe the invention as being 
only those specific characteristics, the claim should not be 
allowed until the claim is amended to recite those specific 
structural or additional functional characteristics. Other-
wise, a claim could be allowed having broad functional lan-
guage which, in reality, is limited to only the specific 
structure or steps disclosed in the specification. This would 
be contrary to public policy of granting patents which pro-
vide adequate notice to the public as to a claim's true scope.

APPLICANT MAY AMEND CLAIMS 

Finally, as in the past, applicant has the opportunity dur-
ing proceedings before the Office to amend the claims so 
that the claimed invention meets all the statutory criteria for 
patentability. An applicant may choose to amend the claim 
by further limiting the function so that there is no longer 
identity of function with that taught by the prior art ele-
ment, or the applicant may choose to replace the claimed 
means plus function limitation with specific structure, 
material or acts that are not described in the prior art.

2185	Related Issues Under 35 U.S.C. 112, 
First or Second Paragraphs

Interpretation of claims as set forth in  MPEP ? 2181 
may create some uncertainty as to what applicant regards as 
the invention. If this issue arises, it should be addressed in a 
rejection under 35 U.S.C. 112, second paragraph. While 
35 U.S.C. 112, sixth paragraph permits a particular form of 
claim limitation, it cannot be read as creating an exception 
either to the description, enablement or best mode require-
ments of the first paragraph or the definiteness requirement 
of the second paragraph of  35 U.S.C. 112. In re Knowlton, 
481 F.2d 1357, 178 USPQ 486 (CCPA 1973).

If a "means or step plus function" limitation recited in a 
claim is not supported by corresponding structure, material 
or acts in the specification disclosure, the following rejec-
tions should be considered:

(A)	under  35 U.S.C. 112, first paragraph, as not being 
supported by an enabling disclosure because the person 
skilled in the art would not know how to make and use the 
invention without a description of elements to perform the 
function. The description of an apparatus with block dia-
grams describing the function, but not the structure, of the 
apparatus is not fatal under the enablement requirement of  
35 U.S.C. 112, first paragraph, as long as the structure is 
conventional and can be determined without an undue 
amount of experimentation. In re Ghiron, 442 F.2d 985, 
991, 169 USPQ 723, 727 (CCPA 1971);

(B)	under  35 U.S.C. 112, second paragraph, as being 
indefinite. In re Dossel, 115 F.3d 942, 946, 42 USPQ2d 
1881, 1884 (Fed. Cir. 1997); and 

(C)	under 35 U.S.C. 102 or 103 where the prior art 
anticipates or renders obvious the claimed subject matter 
including the means or step that performs the function 
specified in the claim, the theory being that since there is 
no corresponding structure, etc., in the specification to limit 
the means or step plus function limitation, an equivalent is 
any element that performs the specified function.

2186	Relationship to the Doctrine of  
Equivalents

The doctrine of equivalents arises in the context of an 
infringement action.  If an accused product or process does 
not literally infringe a patented invention, the accused prod-
uct or process may  be found to infringe under the doctrine 
of equivalents.  The essential objective inquiry is:  "Does 
the accused product or process contain elements identical 
or equivalent to each claimed element of the patented 
invention?" Warner-Jenkinson Co. v. Hilton Davis Chemi-
cal Co., 117 S. Ct. 1040, 41 USPQ2d 1865, 1875 (1997). In 
determining equivalence, "[a]n analysis of the role played 
by each element in the context of the specific patent claim 
will thus inform the inquiry as to whether a substitute ele-
ment matches the function, way, and result of the claimed 
element, or whether the substitute plays a role substantially 
different from the claimed element." 41 USPQ2d at 1875.

35 U.S.C. 112, sixth paragraph permits "means or step 
plus function" limitations in claims to combinations, "with 
the proviso that application of the broad literal language of 
such claims must be limited to only those means that are 
`equivalent' to the actual means shown in the patent specifi-
cation. This is an application of the doctrine of equivalents 
in a restrictive role, narrowing the application of broad lit-
eral claim elements." 41 USPQ2d at 1870. Accordingly, 
decisions involving the doctrine of equivalents should be 
considered, but should not unduly influence a determina-
tion under 35 U.S.C. 112, sixth paragraph during ex parte 
examination.

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