MPEP § 2138 — MPEP § 2138
Current through: 2022-07-01

2138-Pre-AIA 35 U.S.C. 102(g) 
 
 

 
 
 
 
 
 
 
 

 

 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 

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 Manual of Patent Examining Procedure 

 Chapter 2100 

 Section 2138 
 

 
 
 
 
 
 2138 Pre-AIA 35 U.S.C. 102(g) [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF) provisions
 of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a pre-AIA
 effective filing date (before March 16, 2013) and at least one claim with a post-AIA
 effective filing date (on or after March 16, 2013) are subject to the patentability
 requirements in AIA 35 U.S.C. 102 - 103 and
 subject to pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 
 Pre-AIA 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
 invention under this subsection, there shall be considered not only the respective
 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.
 

 
 

 Pre-AIA 35 U.S.C.
 102(g) bars the issuance of a patent where another made the invention
 in the United States before the inventor and had not abandoned, suppressed, or concealed
 it. This section of pre-AIA 35 U.S.C. 102 forms a basis for interference practice. See
 MPEP Chapter
 2300 for more information on interference procedure. See below
 and MPEP §§
 2138.01 - 2138.06 for more information on the
 requirements of pre-AIA
 35 U.S.C. 102(g) .
 

 Pre-AIA 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. 
 

 Pre-AIA 35 U.S.C.
 102(g) may form the basis for an ex parte
 rejection if: (1) the subject matter at issue has been actually reduced to
 practice by another before the inventor’s invention; and (2) there has been no abandonment,
 suppression or concealment. See, e.g., Amgen, Inc. v. Chugai Pharmaceutical
 Co., 927 F.2d 1200, 1205, 18 USPQ2d 1016, 1020 (Fed. Cir. 1991); New
 Idea Farm Equipment Corp. v. Sperry Corp., 916 F.2d 1561, 1566, 16 USPQ2d
 1424, 1428 (Fed. Cir. 1990); E.I. DuPont de Nemours & Co. v. Phillips
 Petroleum Co., 849 F.2d 1430, 1434, 7 USPQ2d 1129, 1132 (Fed. Cir. 1988);
 Kimberly-Clark v. Johnson & Johnson, 745 F.2d 1437, 1444-46, 223
 USPQ 603, 606-08 (Fed. Cir. 1984). To qualify as prior art under pre-AIA 35 U.S.C.
 102(g) , however, there must be evidence that the subject matter was
 actually reduced to practice, in that conception alone is not sufficient. See
 Kimberly-Clark, 745 F.2d at 1445, 223 USPQ at 607. While the filing
 of an application for patent is a constructive reduction to practice, the filing of an
 application does not in itself provide the evidence necessary to show an actual reduction
 to practice of any of the subject matter disclosed in the application as is necessary to
 provide the basis for an ex parte rejection under pre-AIA 35 U.S.C.
 102(g) . Thus, absent evidence showing an actual reduction to practice
 (which is generally not available during ex parte examination), the
 disclosure of a United States patent application publication or patent falls under
 pre-AIA 35 U.S.C.
 102(e) and not under pre-AIA 35 U.S.C. 102(g) .
 Cf. In re Zletz, 893 F.2d 319, 323, 13 USPQ2d 1320, 1323 (Fed. Cir. 1989)
 (the disclosure in a reference United States patent does not fall under pre-AIA 35 U.S.C.
 102(g) but under pre-AIA 35 U.S.C. 102(e) ).
 

 In addition, subject matter qualifying as prior art only under
 pre-AIA 35 U.S.C.
 102(g) may also be the basis for an ex parte 
 rejection under pre-AIA
 35 U.S.C. 103 . See 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, the inventors
 admitted that the subcombination screen of a copending application which issued as a patent
 was earlier conceived than the combination). Pre-AIA 35 U.S.C. 103(c) , however,
 states that subsection (g) of pre-AIA 35 U.S.C. 102 will not preclude
 patentability where subject matter developed by another person, that would otherwise
 qualify under pre-AIA 35
 U.S.C. 102(g) , and the claimed invention of an application under
 examination were owned by the same person, subject to an obligation of assignment to the
 same person, or involved in a joint research agreement, which meets the requirements of
 pre-AIA 35 U.S.C.
 103(c)(2) and (c)(3) , at the time the invention was made. See
 MPEP §
 2146 .
 

 For additional examples of pre-AIA 35 U.S.C. 102(g) issues such as
 conception, reduction to practice and diligence outside the context of interference
 matters, see 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 ), and Kawai v.
 Metlesics, 480 F.2d 880, 178 USPQ 158 (CCPA 1973) (holding constructive
 reduction to practice for foreign 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 [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF)
 provisions of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a
 pre-AIA effective filing date (before March 16, 2013) and at least one claim with a
 post-AIA effective filing date (on or after March 16, 2013) are subject to the
 patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to
 pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 I. PRE-AIA 35 U.S.C. 102(g) IS THE BASIS OF INTERFERENCE PRACTICE Subsection (g) of pre-AIA 35 U.S.C.
 102 is the basis of interference 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);
 Paulik v. Rizkalla, 760 F.2d 1270, 1276-81, 226 USPQ 224, 225
 (Fed. Cir. 1985) (reviews the legislative history of the subsection in a concurring
 opinion by Judge Rich). 35 U.S.C. 135 , 37 CFR Part 41,
 Subparts D and E and MPEP Chapter 2300 . An interference 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
 different inventors or one or more pending applications and one or more unexpired
 patents naming different inventors. The first of many to reduce an invention to
 practice around the same time will be the sole party to obtain a patent in some
 instances, 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 interference is rejected under pre-AIA 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 the claimed invention is the party that must be named as
 the inventor before a patent may be granted. Where it can be shown that a named
 inventor has “derived” an invention from another, a rejection under pre-AIA 35 U.S.C.
 102(f) is proper if applicable. Ex parte
 Kusko, 215 USPQ 972, 974 (Bd. App. 1981) (“most, if not all,
 determinations under [pre-AIA] 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.). 
 

 II. 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 antedate references which are available as prior art
 under pre-AIA
 35 U.S.C. 102(a) or 102(e) . Note, however, in the
 context of 37
 CFR 1.131 , an inventor 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 constructive 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 interference proceeding. Paulik v.
 Rizkalla, 760 F.2d 1270, 226 USPQ 224 (Fed. Cir. 1985). See the
 discussion of abandonment, suppression, and concealment in MPEP §
 2138.03 .
 

 For purposes of analysis under 37 CFR
 1.131 , the conception 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 T D = 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 conception 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
 T D (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 invention 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 reducing the invention to practice and before constructively
 reducing the invention to practice.
 

 A 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 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 T D (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 invention
 to practice and before constructively reducing the invention to practice.
 

 A 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 diligently actually reduced the invention to
 practice, even though this was after B reduced the invention to practice.
 

 
 III. 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
 inventor to show an actual date of invention prior to the effective date of a
 reference or activity applied under pre-AIA 35 U.S.C. 102 or
 103 , as long as the reference is not a statutory bar under
 pre-AIA 35
 U.S.C. 102(b) or a U.S. patent application publication 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 interference rather than an
 affidavit under 37 CFR 1.131 to antedate 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 prior art
 under pre-AIA 35
 U.S.C. 102(g) and is subject to an interference is not open to
 further inquiry under 37 CFR 1.131 during the
 interference proceeding.
 

 IV. 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 pre-AIA 35 U.S.C.
 102 may be used alone or in combination with other references
 under pre-AIA 35
 U.S.C. 103 . But see In re Deckler, 977 F.2d
 1449, 24 USPQ2d 1448 (Fed. Cir. 1992) (Under the principles of res
 judicata and collateral estoppel, 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 available for
 use in an obviousness rejection under 35 U.S.C. 103 .).
 

 

 
 2138.02 “The Invention Was Made in This Country” [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF)
 provisions of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a
 pre-AIA effective filing date (before March 16, 2013) and at least one claim with a
 post-AIA effective filing date (on or after March 16, 2013) are subject to the
 patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to
 pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 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 pre-AIA 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
 pre-AIA 35 U.S.C.
 102(g) has ever been made). 
 

 Subject matter under pre-AIA 35 U.S.C. 102(g) is
 available only if made in this country. Pre-AIA 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 invention is reduced to practice in a foreign country and
 knowledge 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
 evidence of conception of the invention”).
 

 In accordance with pre-AIA 35 U.S.C. 102(g)(1) , a party
 involved in an interference proceeding under pre-AIA 35 U.S.C. 135 or
 291 may establish a date of invention under pre-AIA 35 U.S.C.
 104 . Pre-AIA 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 inventor 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 invention 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 pre-AIA 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” [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF)
 provisions of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a
 pre-AIA effective filing date (before March 16, 2013) and at least one claim with a
 post-AIA effective filing date (on or after March 16, 2013) are subject to the
 patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to
 pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 Pre-AIA 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 suppression and concealment, lost the right to rely on the 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 invention 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 invention 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 filing 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 reduction to practice and the public disclosure
 to avoid the inference of abandonment.
 

 I. DURING AN INTERFERENCE PROCEEDING, AN INFERENCE OF SUPPRESSION OR CONCEALMENT
 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. Shindelar 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 overcome 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 inventorship, 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). 
 

 II. 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— the court identified that a total of 3 months was possibly
 excusable in regard to the filing of an application.).
 

 III. INFERENCE OF SUPPRESSION OR CONCEALMENT IS REBUTTABLE Notwithstanding an inference of suppression or concealment due to
 time(s) of inactivity after reduction to practice, the senior party may still prevail
 if the senior party shows renewed activity on the invention that is just prior to the
 junior party’s entry into field coupled with the diligent filing of an application.
 Lutzker v. Plet, 843 F.2d 1364, 1367-69, 6 USPQ2d 1370, 1371-72 (Fed. Cir.
 1988) (activities directed towards commercialization not sufficient to rebut
 inference); Holmwood v. Cherpeck, 2 USPQ2d 1942, 1945 (Bd. Pat.
 App. & Inter. 1986) (the inference of suppression or concealment may be rebutted
 by showing activity 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 reasonable amount of time should be allowed for
 completion of the research project on the whole series of new compounds, 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.).
 

 IV. 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” [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF)
 provisions of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a
 pre-AIA effective filing date (before March 16, 2013) and at least one claim with a
 post-AIA effective filing date (on or after March 16, 2013) are subject to the
 patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to
 pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 Conception has been defined as “the complete performance of the mental
 part of the inventive act” and it is “the formation in the mind of the inventor of a
 definite and permanent 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 1929). “[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 experimentation 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 conception. Conception must be
 proved by corroborating evidence.); Hybritech Inc. v. Monoclonal Antibodies
 Inc., 802 F. 2d 1367, 1376, 231 USPQ 81, 87 (Fed. Cir. 1986) (Conception 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.”);
 Hitzeman v. Rutter, 243 F.3d 1345, 58 USPQ2d 1161 (Fed. Cir. 2001)
 (Inventor’s “hope” that a genetically altered yeast would produce antigen particles
 having the particle size and sedimentation rates recited in the claims did not establish
 conception, since the inventor did not show that he had a “definite and permanent
 understanding” as to whether or how, or a reasonable expectation that, the yeast would
 produce the recited antigen particles.); 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”).
 

 I. 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 conception.
 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 inventor conceived.). A person who shares in the conception of a claimed
 invention is a joint inventor of that invention. In re VerHoef, 
 888 F.3d 1362, 1366-67, 126 F.2d 1561, 1564-65 (Fed. Cir. 2018).
 

 II. 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. Silvestri v. Grant, 496 F.2d
 593, 596, 181 USPQ 706, 708 (CCPA 1974) (“an accidental and unappreciated duplication
 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”);
 Invitrogen, Corp. v. Clontech Laboratories, Inc., 429 F.3d 1052, 1064,
 77 USPQ2d 1161, 1169 (Fed. Cir. 2005) (In situations where there is unrecognized
 accidental duplication, establishing conception requires evidence that the inventor
 actually made the invention and understood the invention to have the features that
 comprise the inventive subject matter at issue). 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 conception. 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 inventor believed the inventions would work based on initial
 screening tests.) Furthermore, the inventor does not need to appreciate the
 patentability of the invention. Dow Chem. Co. v. Astro-Valcour,
 Inc., 267 F.3d 1334, 1341, 60 USPQ2d 1519, 1523 (Fed. Cir. 2001).
 

 The first to conceive of a species is not necessarily the first to
 conceive of the generic invention. In re Jolley, 308 F.3d 1317,
 1323 n.2, 64 USPQ2d 1901, 1905 n.2 (Fed. Cir. 2002). Further, while conception of a
 species within a genus may constitute 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, Inc. v.
 Chugai Pharmaceutical Co., 927 F.2d 1200, 1206, 18 USPQ2d 1016, 1021
 (Fed. Cir. 1991) (in the isolation 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
 substance, without conception of a structural or equivalent definition of that
 substance, can at most constitute a conception of the substance claimed as a process”
 but cannot 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). See MPEP §§
 2106.04(b) and 2106.04(c) for information on the subject matter
 eligibility of inventions involving isolated genes.
 

 On rare occasions conception and reduction to practice occur
 simultaneously in unpredictable technologies. Alpert v. Slatin, 
 305 F.2d 891, 894, 134 USPQ 296, 299 (CCPA 1962). “[I]n some unpredictable areas of
 chemistry and biology, there is no conception until the invention has been reduced to
 practice.” MacMillan v. Moffett, 432 F.2d 1237, 1234-40, 167 USPQ 550, 552-553 (CCPA
 1970). See also Hitzeman v. Rutter, 243 F.3d 1345, 58 USPQ2d 1161
 (Fed. Cir. 2001) (conception simultaneous with reduction to practice where appellant
 lacked reasonable certainty that yeast’s performance of certain intracellular
 processes would result in the claimed antigen particles); 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).
 

 III. A PREVIOUSLY ABANDONED APPLICATION WHICH WAS NOT COPENDING WITH A SUBSEQUENT
 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 conception.
 In re Costello, 717 F.2d 1346, 1350, 219 USPQ 389, 392 (Fed.
 Cir. 1983).
 

 

 
 2138.05 “Reduction to Practice” [R-01.2024]

 [Editor Note: This MPEP section has limited
 applicability to applications subject to examination under the first inventor
 to file (FITF) provisions of the AIA as set forth in 35 U.S.C. 100
 (note) . Patents and applications that contain (or contained at any
 time) at least one claim with a pre-AIA effective filing date (before March 16, 2013)
 and at least one claim with a post-AIA effective filing date (on or after March 16,
 2013) are subject to the patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to pre-AIA 35 U.S.C.
 102(g) .See MPEP § 2159 et seq. ] 
 

 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 filing of a patent application serves as conception and constructive
 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 application. 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 practice at the time, the subsequent abandonment of that application 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)(The second application was not co-pending with the original
 application and it did not reference the original application. Because of the
 requirements of 35
 U.S.C. 120 had not been satisfied, the filing of the original
 application was not recognized as constructive reduction to practice of the
 invention.).
 

 I. CONSTRUCTIVE REDUCTION TO PRACTICE REQUIRES COMPLIANCE WITH 35 U.S.C. 112(a)
 or PRE-AIA 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(a) or pre-AIA 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 disclosure under the “how to use” and “how to make” requirements
 of 35
 U.S.C. 112(a) or pre-AIA 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 -CH 2 - 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
 utility.). The purpose of the written description requirement is “to ensure that the
 inventor had possession, as of the filing 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 inventor 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 inventor was in possession of the invention of the
 count.). See also Bigham v. Godtfredsen, 857 F.2d 1415, 1417,
 8 USPQ2d 1266, 1268 (Fed. Cir. 1988) (“[t]he generic term halogen comprehends a
 limited number of species, and ordinarily constitutes a sufficient written
 description of the common halogen species,” except where the halogen species are
 patentably distinct). 
 

 II. 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 performed a process that met every element of the interference
 count, and (2) the embodiment or process operated for its intended purpose.”
 Eaton v. Evans, 204 F.3d 1094, 1097, 53 USPQ2d 1696, 1698 (Fed.
 Cir. 2000).
 

 The same evidence sufficient for a constructive reduction 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. See,
 e.g., Scott v. Finney, 34 F.3d 1058, 1062, 32 USPQ2d 1115, 1118-19
 (Fed. Cir. 1994) (citing numerous cases wherein the character of the testing
 necessary to support an actual reduction to practice varied with the complexity of
 the invention and the problem it solved). If a device is so simple, and its purpose
 and efficacy so obvious, construction alone is sufficient to demonstrate 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 necessary 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
 practice can call into question whether reduction to practice has in fact occurred”);
 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”); Birmingham v. Randall, 171 F.2d 957, 80 USPQ 371, 372
 (CCPA 1948) (To establish an actual reduction to practice of an invention directed to
 a method of making a product, it is not enough to show that the method was performed.
 “[S]uch an invention is not reduced to practice until it is established that the
 product made by the process is satisfactory, and [ ] this may require successful
 testing of the product.”). 
 

 III. 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. Wanberg, 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
 duplicate 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 functional 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). 
 

 IV. REDUCTION TO PRACTICE REQUIRES RECOGNITION AND APPRECIATION OF THE
 INVENTION The invention must be recognized and appreciated for a reduction to
 practice to occur. “The rule that conception and reduction to practice cannot be
 established nunc pro tunc simply requires that in order for an experiment to
 constitute an actual reduction to practice, there must have been contemporaneous
 appreciation of the invention at issue by the inventor…. Subsequent testing or later
 recognition may not be used to show that a party had contemporaneous appreciation of
 the invention. However, evidence of subsequent testing may be admitted for the
 purpose of showing that an embodiment was produced and that it met the limitations of
 the count.” Cooper v. Goldfarb, 154 F.3d 1321, 1331, 47 USPQ2d
 1896, 1904 (Fed. Cir. 1998) (citations omitted). 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 recognition 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
 ultimately 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”). 
 

 V. RECOGNITION OF THE INVENTION BY ANOTHER MAY INURE TO THE BENEFIT OF THE
 INVENTOR “Inurement involves a claim by an inventor that, as a matter of
 law, the acts of another person should accrue to the benefit of the inventor.”
 Cooper v. Goldfarb, 154 F.3d 1321, 1331, 47 USPQ2d 1896, 1904
 (Fed. Cir. 1998). Before a non-inventor’s recognition of the utility of the invention
 can inure to the benefit of the inventor, the following three-prong test must be met:
 (1) the inventor must have conceived of the invention, (2) the inventor must have had
 an expectation that the embodiment tested would work for the intended purpose of the
 invention, and (3) the inventor must have submitted the embodiment for testing for
 the intended purpose of the invention. Genentech, Inc. v. Chiron
 Corp., 220 F.3d 1345, 1354, 55 USPQ2d 1636, 1643 (Fed. Cir. 2000). In
 Genentech, a non-inventor hired by the inventor to test yeast
 samples for the presence of the fusion protein encoded by the DNA construct of the
 invention recognized the growth-enhancing property of the fusion protein, but did not
 communicate this recognition to the inventor. The court found that because the
 inventor did not submit the samples for testing growth-promoting activity, the
 intended purpose of the invention, the third prong was not satisfied and the
 uncommunicated recognition of the activity of the fusion protein by the non-inventor
 did not inure to the benefit of the inventor. See also Cooper v.
 Goldfarb, 240 F.3d 1378, 1385, 57 USPQ2d 1990, 1995 (Fed. Cir. 2001)
 (Cooper sent to Goldfarb samples of a material for use in vascular grafts. At the
 time the samples were sent, Cooper was unaware of the importance of the fibril length
 of the material. Cooper did not at any time later convey to, or request from,
 Goldfarb any information regarding fibril length. Therefore, Goldfarb’s determination
 of the fibril lengths of the material could not inure to Cooper’s benefit.). 
 

 VI. IN AN INTERFERENCE PROCEEDING, ALL LIMITATIONS OF A COUNT MUST BE REDUCED TO
 PRACTICE The device reduced to practice must include every limitation 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 reduction to practice. Meitzner v. Corte, 537 F.2d 524,
 528, 190 USPQ 407, 410 (CCPA 1976). 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 conform to the proofs). 
 

 VII. 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 utility); 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 zeolites 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 animals for somewhat different pharmaceutical
 purposes than those asserted in the specification for humans.); Rey-Bellet
 v. Engelhardt, 493 F.2d 1380, 1384, 181 USPQ 453, 455 (CCPA 1974) (Two
 categories of tests on laboratory animals 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.).
 

 VIII. 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 preparation 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 intermediate from the first
 intermediate. However, a strong probability 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 possible 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 suggested uses. Reasonable correlation between the two is sufficient for an actual
 reduction to practice.).
 

 

 
 2138.06 “Reasonable Diligence” [R-01.2024]

 [Editor Note: This MPEP section has limited applicability to
 applications subject to examination under the first inventor to file (FITF)
 provisions of the AIA as set forth in 35 U.S.C. 100 (note) . Patents and
 applications that contain (or contained at any time) at least one claim with a
 pre-AIA effective filing date (before March 16, 2013) and at least one claim with a
 post-AIA effective filing date (on or after March 16, 2013) are subject to the
 patentability requirements in AIA 35 U.S.C.
 102 - 103 and subject to
 pre-AIA 35
 U.S.C. 102(g) .See MPEP §
 2159 et seq.] 

 The diligence of pre-AIA 35 U.S.C. 102(g) relates to
 reasonable “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
 particular invention involved….” Emery v. Ronden, 188 USPQ 264, 268
 (Bd. Pat. Inter. 1974). 
 

 I. CRITICAL PERIOD FOR ESTABLISHING DILIGENCE BETWEEN ONE WHO WAS FIRST TO
 CONCEIVE BUT LATER TO REDUCE TO PRACTICE 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 immediately preceding the conception date of the second
 conceiver 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., conception 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 constructive 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 that was filed within the twelve month period prescribed by
 35 U.S.C.
 119 )). 
 

 II. THE ENTIRE PERIOD DURING WHICH DILIGENCE IS REQUIRED MUST BE ACCOUNTED FOR BY
 EITHER AFFIRMATIVE ACTS OR ACCEPTABLE EXCUSES “A patent owner need not prove the inventor
 continuously exercised reasonable diligence throughout the
 critical period; it must show there was reasonably continuous 
 diligence.” Perfect Surgical Techniques, Inc. v. Olympus Am.,
 Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016)
 (emphasis in original) (citing Tyco Healthcare Grp. v. Ethicon EndoSurgery,
 Inc., 774 F.3d 968, 975, 112 USPQ2d 1979 (Fed. Cir. 2014) and
 Monsanto Co. v. Mycogen Plant Sci., Inc., 261 F.3d 1356, 1370,
 59 USPQ2d 1930, 1939 (Fed. Cir. 2001)).
 

 An inventor 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 stating 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 inactivity during the
 critical period shows a lack of diligence. 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) (Evidence of diligence 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, 255 F.2d 419, 423, 118 USPQ 96, 100 (CCPA 1958) (Being last to
 reduce to practice, party cannot prevail unless the party has shown that the party
 was first to conceive and that the party 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 university 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
 testing 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 sufficient 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 hardware 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….”).
 

 Examiners should weigh the body of evidence to make
 the determination of whether there was reasonably continuous diligence for the entire
 critical period. This determination should be made with the purpose of the diligence
 requirement in mind, which “is to assure that, in light of the evidence as a whole,
 ‘the invention was not abandoned or unreasonably delayed.’” Perfect Surgical
 Techniques, Inc. v. Olympus Am., Inc. ( Perfect
 Surgical ), 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016)
 (citations omitted). In Perfect Surgical , the Federal Circuit
 stated:
 

 
 
 Under this standard, an inventor is not
 required to work on reducing his invention to practice every day during the
 critical period. … And periods of inactivity within the critical period do not
 automatically vanquish a patent owner's claim of reasonable diligence…. In
 determining whether an invention antedates another, the point of the diligence
 analysis is not to scour the patent owner's corroborating evidence in search of
 intervals of time where the patent owner has failed to substantiate some sort
 of activity. It is to assure that, in light of the evidence as a whole, “the
 invention was not abandoned or unreasonably delayed.” ... That an inventor
 overseeing a study did not record its progress on a daily, weekly, or even
 monthly basis does not mean the inventor necessarily abandoned his invention or
 unreasonably delayed it. The same logic applies to the preparation of a patent
 application: the absence of evidence that an inventor and his attorney revised
 or discussed the application on a daily basis is alone insufficient to
 determine that the invention was abandoned or unreasonably delayed. One must
 weigh the collection of evidence over the entire critical period to make such a
 determination.
 

 
 

 
 Our decision in In re
 Mulder, 716 F.2d 1542, 1542-46 [219 USPQ 189] (Fed. Cir. 1983),
 does not instruct otherwise. The Board cites In re Mulder 
 for the proposition that “[e]ven a short period of unexplained inactivity may
 be sufficient to defeat a claim of diligence.” …. In In re
 Mulder, a competing reference was published just days before the
 patent at issue was constructively reduced to practice. …. The patent owner was
 tasked with showing reasonable diligence during a critical period lasting only
 two days. ... But the patent owner did not produce any evidence of diligence
 during the critical period. ... Nor could it point to any activity during the
 months between the drafting of the application and the start of the critical
 period. ... Although the critical period spanned just two days, we declined to
 excuse the patent owner's complete lack of evidence. ... In re
 Mulder does not hold that an inventor's inactivity during a
 portion of the critical period can, without more, destroy a patent owner's
 claim of diligence.
 

 
 

 Perfect Surgical , 841 F.3d at 1009,
 120 USPQ2d at 1609 (citations omitted).
 

 III. 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 invention in issue. Naber v.
 Cricchi, 567 F.2d 382, 384, 196 USPQ 294, 296 (CCPA 1977),
 cert. denied, 439 U.S. 826 (1978). See also Scott v.
 Koyama, 281 F.3d 1243, 1248-49, 61 USPQ2d 1856, 1859 (Fed. Cir. 2002)
 (Activities directed at building a plant to practice the claimed process of producing
 tetrafluoroethane on a large scale constituted efforts toward actual reduction to
 practice, and thus were evidence of diligence. The court distinguished cases where
 diligence was not found because inventors either discontinued development or failed
 to complete the invention while pursuing financing or other commercial activity.);
 In re Jolley, 308 F.3d 1317, 1326-27, 64 USPQ2d 1901, 1908-09
 (Fed. Cir. 2002) (diligence found based on research and procurement activities
 related to the subject matter of the interference count). “[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 compounds that were considered to be part of the same
 invention 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 concerns
 related subject matter.” Gunn v. Bosch, 181 USPQ 758, 761 (Bd.
 Pat. Inter. 1973) (An actual reduction to practice of the invention at issue which
 occurred when the inventor was working on a different invention “was fortuitous, and
 not the result of a continuous intent or effort to reduce to practice the invention
 here in issue. Such fortuitousness 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 combination.); 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. Schoenwald, 15 USPQ2d 1507
 (Bd. Pat. App. & Inter. 1990) (principles of diligence must be given to
 inventor’s circumstances including skill and time; requirement of corroboration
 applies only to testimony of inventor); Huelster v. Reiter, 168
 F.2d 542, 78 USPQ 82 (CCPA 1948) (an inventor who was not able to make an actual
 reduction to practice of the invention, must also show why constructive reduction to
 practice by filing an application was not possible).
 

 IV. DILIGENCE REQUIRED IN PREPARING AND FILING PATENT APPLICATION The diligence of an 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 signature than it
 is one of disclosure. An attorney does not prepare a patent application on behalf of
 particular named persons, but on behalf of the true inventive entity. Six days to
 execute and file application is acceptable. Haskell v. Coleburne, 
 671 F.2d 1362, 213 USPQ 192, 195 (CCPA 1982). See also Bey v.
 Kollonitsch, 806 F.2d 1024, 231 USPQ 967 (Fed. Cir. 1986) (Reasonable
 diligence is all that is required of the attorney. Reasonable diligence is
 established if the attorney worked reasonably hard on the application during the
 continuous critical period. If the attorney has a reasonable backlog of unrelated
 cases which the attorney takes up in chronological 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.). In “the preparation" of a patent application, "the absence of evidence
 that an inventor and his attorney revised or discussed the application on a daily
 basis is alone insufficient to determine that the invention was abandoned or
 unreasonably delayed." Perfect Surgical Techniques, Inc. v. Olympus Am.,
 Inc., 841 F.3d 1004, 1009, 120 USPQ2d 1605, 1609 (Fed. Cir. 2016). 
 

 V. END OF DILIGENCE PERIOD IS MARKED BY EITHER ACTUAL OR CONSTRUCTIVE REDUCTION
 TO PRACTICE “[I]t is of no moment that the end of that period [for diligence] is
 fixed by a constructive, rather than an actual, reduction to practice.”
 Justus v. Appenzeller, 177 USPQ 332, 340-41 (Bd. Pat. Inter.
 1971).
 

 

 [top] 

 

 

 
 

 
 

 

 

 

 
 
 
 2101-2102-[Reserved] 

 2103-Patent Examination Process 

 2104-Requirements of 35 U.S.C. 101 
 2104.01-Barred by Atomic Energy Act 

 
 

 2105-Patent Eligible Subject Matter — Living Subject Matter 

 2106-Patent Subject Matter Eligibility 
 2106.01-[Reserved] 

 2106.02-[Reserved] 

 2106.03-Eligibility Step 1: The Four Categories of Statutory Subject Matter 

 2106.04-Eligibility Step 2A: Whether a Claim is Directed to a Judicial Exception 
 2106.04(a)-Abstract Ideas 
 2106.04(a)(1)-Examples of Claims That Do Not Recite Abstract Ideas 

 2106.04(a)(2)-Abstract Idea Groupings 

 2106.04(a)(3)-Tentative Abstract Ideas 

 
 

 2106.04(b)-Laws of Nature, Natural Phenomena & Products of Nature 

 2106.04(c)-The Markedly Different Characteristics Analysis 

 2106.04(d)-Integration of a Judicial Exception Into A Practical Application 
 2106.04(d)(1)-Evaluating Improvements in the Functioning of a Computer, or an Improvement to Any Other Technology or Technical Field in
 Step 2A Prong Two 

 2106.04(d)(2)-Particular Treatment and Prophylaxis in Step 2A Prong Two 

 
 

 
 

 2106.05-Eligibility Step 2B: Whether a Claim Amounts to Significantly More 
 2106.05(a)-Improvements to the Functioning of a Computer or To Any Other Technology or Technical Field 

 2106.05(b)-Particular Machine 

 2106.05(c)-Particular Transformation 

 2106.05(d)-Well-Understood, Routine, Conventional Activity 

 2106.05(e)-Other Meaningful Limitations 

 2106.05(f)-Mere Instructions To Apply An Exception 

 2106.05(g)-Insignificant Extra-Solution Activity 

 2106.05(h)-Field of Use and Technological Environment 

 
 

 2106.06-Streamlined Analysis 
 2106.06(a)-Eligibility is Self Evident 

 2106.06(b)-Clear Improvement to a Technology or to Computer Functionality 

 
 

 2106.07-Formulating and Supporting Rejections For Lack Of Subject Matter Eligibility 
 2106.07(a)-Formulating a Rejection For Lack of Subject Matter Eligibility 
 2106.07(a)(1)-Form Paragraphs for use in Lack of Subject Matter Eligibility Rejections 

 
 

 2106.07(b)-Evaluating Applicant’s Response 

 2106.07(c)-Clarifying the Record 

 
 

 
 

 2107-Guidelines for Examination of Applications for Compliance with the Utility Requirement 
 2107.01-General Principles Governing Utility Rejections 

 2107.02-Procedural Considerations Related to Rejections for Lack of Utility 

 2107.03-Special Considerations for Asserted Therapeutic or Pharmacological Utilities 

 
 

 2108-[Reserved] 

 2109-Inventorship 

 2109.01-Joint Inventorship 

 2110-[Reserved] 

 2111-Claim Interpretation; Broadest Reasonable Interpretation 
 2111.01-Plain Meaning 

 2111.02-Effect of Preamble 

 2111.03-Transitional Phrases 

 2111.04-“Adapted to,” “Adapted for,” “Wherein,” “Whereby,” and Contingent Clauses 

 2111.05-Functional and Nonfunctional Descriptive Material 

 
 

 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-Novel, Nonobvious Starting Material or End Product 
 2116.01-Novel, Nonobvious Starting Material or End Product 

 
 

 2117-Markush Claims 

 2118-2119-[Reserved] 

 2120-Rejection on Prior Art 
 2120.01-Rejections Under 35 U.S.C. 102(a)(1) and (a)(2) and Pre-AIA 35 U.S.C. 102(a), (b), or (e): Printed Publication or Patent 

 2120.02-Rejections Under 35 U.S.C. 102(a)(1) or Pre-AIA 35 U.S.C. 102(a) or (b): Knowledge by Others, or Public Use, or On Sale 

 
 

 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 Reference Must be Prior Art 
 2124.01-Tax Strategies Deemed Within the Prior Art 

 
 

 2125-Drawings as Prior Art 

 2126-Availability of a Document as a “Patent” for Purposes of Rejection Under 35 U.S.C. 102(a) or Pre-AIA 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 

 2130-[Reserved] 

 2131-Anticipation — Application of 35 U.S.C. 102 
 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 or Disparaging Prior Art 

 
 

 2132-Pre-AIA 35 U.S.C. 102(a) 
 2132.01-Overcoming a Pre-AIA 35 U.S.C. 102(a) Rejection based on a Printed Publication or Patent 

 
 

 2133-Pre-AIA 35 U.S.C. 102(b) 
 2133.01-Rejections of Continuation-In-Part (CIP) Applications 

 2133.02-Rejections Based on Publications and Patents 
 2133.02(a)-Overcoming a Pre-AIA 35 U.S.C. 102(b) Rejection Based on a Printed Publication or Patent 

 
 

 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-Pre-AIA 35 U.S.C. 102(c) 

 2135-Pre-AIA 35 U.S.C. 102(d) 
 2135.01-The Four Requirements of Pre-AIA 35 U.S.C. 102(d) 

 
 

 2136-Pre-AIA 35 U.S.C. 102(e) 
 2136.01-Status of Unpublished or Published as Redacted U.S. Application as a Reference Under Pre-AIA 35 U.S.C. 102(e) 

 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 Pre-AIA 35 U.S.C. 102(e) 
 2136.05(a)-Antedating a Pre-AIA 35 U.S.C. 102(e) Reference 

 2136.05(b)-Showing The Reference Is Describing An Inventor's Or At Least One Joint Inventor's Own Work 

 
 

 
 

 2137-Pre-AIA 35 U.S.C. 102(f) 
 2137.01-[Reserved] 

 2137.02-[Reserved] 

 
 

 2138-Pre-AIA 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” 

 
 

 2139-Rejections Under Pre-AIA 35 U.S.C. 102 
 2139.01-Effective Filing Date of a Claimed Invention Under Pre-AIA 35 U.S.C. 102 

 2139.02-Determining Whether To Apply Pre-AIA 35 U.S.C. 102(a), (b), or (e) 

 2139.03-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 102 

 
 

 2140-[Reserved] 

 2141-Examination Guidelines for Determining Obviousness Under 35 U.S.C. 103 
 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-Examples of 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 Considered 

 
 

 2144-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 Similar and Overlapping Ranges, Amounts, and Proportions 

 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 and Evidence 

 2146-Pre-AIA 35 U.S.C. 103(c) 
 2146.01-Prior Art Disqualification Under Pre-AIA 35 U.S.C. 103(c) 

 2146.02-Establishing Common Ownership or Joint Research Agreement Under Pre-AIA 35 U.S.C. 103(c) 

 2146.03-Examination Procedure With Respect to Pre-AIA 35 U.S.C. 103(c) 
 2146.03(a)-Provisional Rejection (Obviousness) Under 35 U.S.C. 103(a) Using Provisional Prior Art Under Pre-AIA 35 U.S.C. 102(e) 

 
 

 
 

 2147-Biotechnology Process Applications; Pre-AIA 35 U.S.C. 103(b) 

 2148-Form Paragraphs for Use in Rejections Under Pre-AIA 35 U.S.C. 103 

 2149-[Reserved] 

 2150-Examination Guidelines for 35 U.S.C. 102 and 103 as Amended by the First Inventor To File Provisions of the Leahy-Smith America
 Invents Act 

 2151-Overview of the Changes to 35 U.S.C. 102 and 103 in the AIA 

 2152-Detailed Discussion of AIA 35 U.S.C. 102(a) and (b) 
 2152.01-Effective Filing Date of the Claimed Invention 

 2152.02-Prior Art Under AIA 35 U.S.C. 102(a)(1) (Patented, Described in a Printed Publication, or in Public Use, on Sale, or Otherwise
 Available to the Public) 
 2152.02(a)-Patented 

 2152.02(b)-Described in a Printed Publication 

 2152.02(c)-In Public Use 

 2152.02(d)-On Sale 

 2152.02(e)-Otherwise Available to the Public 

 2152.02(f)-No Requirement of “By Others” 

 
 

 2152.03-Admissions 

 2152.04-The Meaning of “Disclosure” 

 2152.05-Determining Whether To Apply 35 U.S.C. 102(a)(1) or 102(a)(2) 

 2152.06-Overcoming a 35 U.S.C. 102(a)(1) or 102(a)(2) Rejection 

 2152.07-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 102 

 
 

 2153-Prior Art Exceptions Under 35 U.S.C. 102(b)(1) to AIA 35 U.S.C. 102(a)(1) 
 2153.01-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(A) To AIA 35 U.S.C. 102(a)(1) (Grace Period Inventor-Originated Disclosure
 Exception) 
 2153.01(a)-Grace Period Inventor-Originated Disclosure Exception 

 2153.01(b)-[Reserved] 

 
 

 2153.02-Prior Art Exception Under AIA 35 U.S.C. 102(b)(1)(B) to AIA 35 U.S.C. 102(a)(1) (Inventor-Originated Prior Public Disclosure
 Exception) 

 
 

 2154-Provisions Pertaining to Subject Matter in a U.S. Patent or Application Effectively Filed Before the Effective Filing Date
 of the Claimed Invention 
 2154.01-Prior Art Under AIA 35 U.S.C. 102(a)(2) “U.S. Patent Documents” 
 2154.01(a)-WIPO Published Applications 

 2154.01(b)-Determining When Subject Matter Was Effectively Filed Under AIA 35 U.S.C. 102(d) 

 2154.01(c)-Requirement Of “Names Another Inventor” 

 2154.01(d)-Provisional Rejections Under 35 U.S.C. 102(a)(2); Reference Is a Copending U.S. Patent Application 

 
 

 2154.02-Prior Art Exceptions Under 35 U.S.C. 102(b)(2) to AIA 35 U.S.C. 102(a)(2) 
 2154.02(a)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(A) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Disclosure Exception) 

 2154.02(b)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(B) to AIA 35 U.S.C. 102(a)(2) (Inventor-Originated Prior Public Disclosure
 Exception) 

 2154.02(c)-Prior Art Exception Under AIA 35 U.S.C. 102(b)(2)(C) to AIA 35 U.S.C. 102(a)(2) (Common Ownership or Obligation of Assignment) 

 
 

 
 

 2155-Use of Affidavits or Declarations Under 37 CFR 1.130 To Overcome Prior Art Rejections 
 2155.01-Showing That the Disclosure Was Made by the Inventor or a Joint Inventor 

 2155.02-Showing That the Subject Matter Disclosed Had Been Previously Publicly Disclosed by the Inventor or a Joint Inventor 

 2155.03-Showing That the Disclosure was Made, or That Subject Matter had Been Previously Publicly Disclosed, by Another Who Obtained
 the Subject Matter Disclosed Directly or Indirectly From the Inventor or a Joint Inventor 

 2155.04-Enablement 

 2155.05-Who May File an Affidavit or Declaration Under 37 CFR 1.130 

 2155.06-Situations in Which an Affidavit or Declaration Is Not Available 

 
 

 2156-Joint Research Agreements 

 2157-Improper Naming of Inventors 

 2158-AIA 35 U.S.C. 103 
 2158.01-Form Paragraphs for Use in Rejections Under AIA 35 U.S.C. 103 

 
 

 2159-Applicability Date Provisions and Determining Whether an Application Is Subject to the First Inventor To File Provisions of
 the AIA 
 2159.01-Applications Filed Before March 16, 2013 

 2159.02-Applications Filed on or After March 16, 2013 

 2159.03-Applications Subject to the AIA but Also Containing a Claimed Invention Having an Effective Filing Date Before March 16, 2013 

 2159.04-Applicant Statement in Transition Applications Containing a Claimed Invention Having an Effective Filing Date on or After
 March 16, 2013 

 
 

 2160-[Reserved] 

 2161-Three Separate Requirements for Specification Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 
 2161.01-Computer Programming, Computer Implemented Inventions, and 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 
 

 2162-Policy Underlying 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2163-Guidelines for the Examination of Patent Applications Under the 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, first paragraph,
 “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 and Prophetic Examples 

 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 — Biological and Chemical Cases 

 2164.06(c)-Examples of Enablement Issues – Computer Programming 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 

 
 

 2166-Rejections Under 35 U.S.C. 112(a) or Pre-AIA 35 U.S.C. 112, First Paragraph 

 2167-2170-[Reserved] 

 2171-Two Separate Requirements for Claims Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2172-Subject Matter Which the Inventor or a Joint Inventor Regards as The Invention 
 2172.01-Unclaimed Essential Subject Matter 

 
 

 2173-Claims Must Particularly Point Out and Distinctly Claim the Invention 
 2173.01-Interpreting the Claims 

 2173.02-Determining Whether Claim Language is Definite 

 2173.03-Correspondence Between Specification and Claims 

 2173.04-Breadth Is Not Indefiniteness 

 2173.05-Specific Topics Related to Issues Under 35 U.S.C. 112(b) or Pre-AIA 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(l)-[Reserved] 

 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-Practice Compact Prosecution 

 
 

 2174-Relationship Between the Requirements of 35 U.S.C. 112(a) and (b) or Pre-AIA 35 U.S.C. 112, First and Second Paragraphs 

 2175-Form Paragraphs for Use in Rejections Under 35 U.S.C. 112(b) or Pre-AIA 35 U.S.C. 112, Second Paragraph 

 2176-2180-[Reserved] 

 2181-Identifying and Interpreting a 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph Limitation 

 2182-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(a) or (b) and Pre-AIA 35 U.S.C. 112, First or Second Paragraphs 

 2186-Relationship to the Doctrine of Equivalents 

 2187-Form Paragraphs for Use Relating to 35 U.S.C. 112(f) or Pre-AIA 35 U.S.C. 112, Sixth Paragraph 

 2188-2189-[Reserved] 

 2190-Prosecution Laches and Res Judicata 

 

 

 
 

 
 
 

 
 

 

 
 
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