Court Opinion

ID: 209904
Source: CourtListenerOpinion
Date Created: 2011-03-13 08:01:09+00
Date Added: 2024-06-11T17:27:58.638776
License: Public Domain

NOTE: This disposition is nonprecedential.

  United States Court of Appeals for the Federal Circuit

                                         2007-1349

              GENERAL ATOMICS DIAZYME LABORATORIES DIVISION,

                                                       Plaintiff/Counterclaim Defendant-
                                                       Appellee,

                                            and

                   CAROLINA LIQUID CHEMISTRIES CORPORATION,

                                                       Counterclaim/Defendant-
                                                       Appellee,

                                             v.

                                    AXIS-SHIELD ASA,

                                                       Defendant/Counterclaimant-
                                                       Appellant.

        Steven E. Comer, Morrison & Foerster LLP, of San Diego, California, argued for
plaintiff/counterclaim defendant-appellee and counterclaim/defendant-appellee. With him
on the brief were David C. Doyle, Peng Chen, Anders T. Aannestad, and Brian M. Kramer.

       Timothy P. Walker, Kirkpatrick & Lockhart, Preston Gates Ellis, LLP, of San
Francisco, California, argued for defendant/counterclaimant-appellant. Of counsel on the
brief was Paul C. Nyquist, Voss, Cook & Thel LLP, of Newport Beach, California.

Appealed from: United States District Court for the Northern District of California

Judge Susan Illston
                         NOTE: This disposition is nonprecedential.

United States Court of Appeals for the Federal Circuit

                                       2007-1349

            GENERAL ATOMICS DIAZYME LABORATORIES DIVISION,

                                                       Plaintiff/Counterclaim Defendant-
                                                       Appellee,

                                           and

                CAROLINA LIQUID CHEMISTRIES CORPORATION,

                                                       Counterclaim/Defendant-
                                                       Appellee,

                                            v.

                                   AXIS-SHIELD ASA,

                                                       Defendant/Counterclaimant-
                                                       Appellant.

      Appeal from the United States District Court for the Northern District of
      California in Case No. 3:05-CV-04074, Judge Susan Illston.

                                _____________________

                                DECIDED: May 12, 2008
                                _____________________

Before LOURIE, GAJARSA, and DYK, Circuit Judges.

LOURIE, Circuit Judge.
       Axis-Shield ASA (“Axis-Shield”) appeals from the final judgment of the U.S.

District Court for the Northern District of California finding noninfringement of Axis-

Shield’s patents by General Atomics, Diazyme Laboratories Division and Carolina Liquid

Chemistries Corporation (collectively “General Atomics”). Because we conclude that

the district court did not err in its claim construction and thus properly granted summary

judgment of noninfringement, we affirm.

                                     BACKGROUND

       Axis-Shield is the assignee of the patents in suit, viz., U.S. Patents 5,631,127

(“the ’127 patent”) and 5,958,717 (“the ’717 patent”). The patents relate to methods and

kits for assaying homocysteine in a sample such as blood, plasma, or urine.

Homocysteine is an intermediary amino acid produced in the body when methionine is

metabolized to cysteine.      ’127 patent col.1 ll.8-14.      Under normal conditions,

homocysteine is quickly metabolized and its concentration is virtually negligible. Id.

Elevated levels of homocysteine, however, have been associated with the presence of

atherosclerosis and other cardiac and vascular diseases. Id. at col.1 ll.42-29. Thus, the

detection of homocysteine levels in biological samples is of great clinical significance.

Id. at col.1 ll.15-16.

       Claim 1 of the ’127 patent, the only independent claim of that patent, is a

representative claim. 1 That claim reads as follows:

       1. In a method for assaying homocysteine in a sample, said method
       comprising the steps of

       1
         The ’127 and ’717 patents derive from the same parent application and have
nearly identical specifications. For ease of reference, throughout the opinion we will cite
the ’127 patent when referencing the common specification.

2007-1349                                   2
       (i) contacting said sample with a homocysteine converting enzyme and at
       least one substrate for said enzyme other than homocysteine, and

       (ii) assessing an analyte which is a substrate for said enzyme,

       wherein the improvement comprises in step (i) contacting said sample with
       a said substrate other than homocysteine and in step (ii) without
       chromatographic separation assessing a non-labelled analyte selected
       from the group consisting of a homocysteine co-substrate and the
       homocysteine conversion products of the enzymic conversion of
       homocysteine by said enzyme.

Id. claim 1 (emphases added).       Claim 1 of the ’717 patent, which is also the only

independent claim of that patent, contains similar claim language. That claim reads as

follows:

       1. In a method for assaying homocysteine in a sample, said method
       comprising the steps of

       (i) contacting said sample with a homocysteine-converting enzyme and

       (ii) assessing an analyte,

       wherein the improvement comprises in step (ii) without chromatographic
       separation assessing a non-labelled analyte selected from the group
       consisting of the homocysteine conversion products of the enzymic
       conversion of homocysteine by said enzyme.

’717 patent claim 1 (emphases added). The claimed methods thus involve the steps of

contacting the sample with a homocysteine converting enzyme and assessing an

analyte. For the ’717 patent, the analyte must be “selected from the group consisting of

the homocysteine conversion products of the enzymic conversion of homocysteine by

[the homocysteine converting] enzyme.” The ’127 patent, in contrast, requires that the

analyte be selected from either the “homocysteine co-substrate” or the “homocysteine

conversion products of the enzymic conversion of homocysteine by said enzyme.” In

addition, both patents specify that chromatographic separation, a time-consuming and

2007-1349                                   3
cumbersome prior art method that “requires highly specialized and sophisticated

equipment,” is not used to assess the analyte. ’127 patent col.2 ll.6-9.

      General Atomics manufactures and sells enzymatic homocysteine assays for the

detection of homocysteine levels in human samples. For purposes of this appeal, the

accused assay detects the level of homocysteine in a sample in the following general

manner: 1) a co-substrate referred to as S-adenosyl-L-methionine (“SAM”) is added to

the sample; 2) an enzyme referred to as homocysteine-methionine methyl transferase

(“HMTase”) is then added; 3) the HMTase acts to remove a methyl group from the co-

substrate SAM and attach it to the homocysteine, converting the homocysteine into

methionine and SAM into S-adenosyl-L-homocysteine (“SAH”); 4) simultaneously, a

second enzyme is added, SAH-hydrolase, which catalyzes a reaction that converts SAH

to adenosine and non-sample homocysteine; 5) additional steps occur, involving

adenosine deaminase and spectrophotometric monitoring, to determine the level of

SAH produced. Gen. Atomics v. Axis-Shield, No. 05-4074, 2007 WL 1089698, at *3-4

(N.D. Cal. Apr. 11, 2007). 2 Those steps can be graphically depicted in the following

manner:

      2
         The parties disputed certain aspects of the process employed in the accused
assay. For purposes of summary judgment, however, the court drew all reasonable
inferences in favor of Axis-Shield as the nonmoving party and accepted as true Axis-
Shield’s characterization of the process. Id. at *3-5. The description of the accused
assay above is representative of Axis-Shield’s characterization.
2007-1349                                   4
The level of SAH present in the accused assay is proportional to the level of

homocysteine in the sample.          Thus, “measuring SAH allows the amount of

homocysteine to be determined.” Id.

       Axis-Shield informed General Atomics of its belief that its enzymatic

homocysteine assays infringe the ’127 and ’717 patents. In October 2005, General

Atomics filed a declaratory judgment action against Axis-Shield seeking a declaration

that its products do not infringe and that the patents in suit were invalid and

unenforceable.   In response, Axis-Shield counterclaimed, asserting claims of patent

infringement. In addition to the patents in suit, Axis-Shield originally asserted two other

patents, viz., U.S. Patents 6,063,581 (“the ’581 patent”) and 5,827,645 (“the ’645

patent”).   All four patents named Erling Sundrehagen as the inventor and Axis

Biochemicals as the assignee. Early in the case, however, Axis-Shield dismissed its

claims regarding the ’581 and ’645 patents.

       On March 3, 2006, pursuant to the Northern District of California’s Patent Local

Rules, Axis-Shield served its preliminary infringement contentions and identified its first

infringement theory. Axis-Shield asserted that the accused assay infringes the patents

in suit based on the manner in which the HMTase enzyme is used in the assay. In

particular, Axis-Shield asserted that in the accused assay the sample homocysteine

2007-1349                                     5
interacts with HMTase enzyme and SAM, which Axis-Shield characterized, respectively,

as the “homocysteine converting enzyme” and the “homocysteine co-substrate.” Axis-

Shield further asserted that the enzymatic reaction forms two “homocysteine conversion

products,” viz., methionine and SAH, and that the accused assay assesses the level of

SAH without chromatographic separation.       Based on those characterizations, Axis-

Shield contended that the accused assay met all of the limitations of the asserted

claims. That infringement theory was referred to as the “HMTase infringement theory.”

      On April 14, 2006, General Atomics moved for summary judgment based on

Axis-Shield’s HMTase infringement theory. While that motion was pending, Axis-Shield

moved to amend its preliminary infringement contentions.      In doing so, Axis-Shield

asserted an alternative infringement theory, referred to as the “SAH-hydrolase

infringement theory.” That theory focused on the latter stage of the assay during which

the level of SAH is determined. Axis-Shield argued that the SAH-hydrolase acts as the

“homocysteine converting enzyme,” adenosine acts as the “homocysteine co-substrate,”

and SAH acts as the “homocysteine conversion product.”

      On July 19, 2006, the district court granted General Atomics’ motion for summary

judgment.   The court focused on the “assessing” claim limitation required by both

patents in suit. Claim 1 of the ’127 patent requires “assessing a non-labelled analyte

selected from the group consisting of a homocysteine co-substrate and the

homocysteine conversion products of the enzymic conversion of homocysteine by said

enzyme.”    Claim 1 of the ’717 patent, in contrast, only requires “assessing a non-

labelled analyte selected from the group consisting of the homocysteine conversion

products of the enzymic conversion of homocysteine by said enzyme.” Based on that

2007-1349                                 6
language, the district court determined that in order to infringe, the analyte assessed in

the accused assay must be either a “homocysteine co-substrate” or a “homocysteine

conversion product[] of the enzymic conversion of homocysteine by said enzyme.” After

construing those claim terms, the court concluded that the SAH produced in General

Atomics’ assay was neither a “homocysteine co-substrate” nor a “homocysteine

conversion product[] of the enzymic conversion of homocysteine by said enzyme” and

granted summary judgment in favor of General Atomics.

      On August 7, 2006, the district court granted Axis-Shield’s pending motion to

amend its preliminary infringement contentions. The court issued a claim construction

ruling on September 26, 2006.      General Atomics then brought a second summary

judgment motion based on Axis-Shield’s SAH-hydrolase infringement theory. On April

11, 2007, the court granted the motion. The court noted that under Axis-Shield’s new

infringement theory, SAH is the analyte that is assessed.         The court determined,

however, that Axis-Shield failed to show that the SAH is a “homocysteine conversion

product[] of the enzymic conversion of homocysteine by said enzyme.” Under the new

theory, the term “said enzyme” referred to SAH-hydrolase, and Axis-Shield could not

show that the SAH produced in the assay was a product of the SAH-hydrolase enzymic

conversion of homocysteine. As such, the court concluded that Axis-Shield failed to

show that the accused assay met the “assessing a non-labelled analyte” limitation

required by the asserted claims and again granted summary judgment of

noninfringement in favor of General Atomics.

2007-1349                                   7
       On May 1, 2007, the parties stipulated to the dismissal of all outstanding claims.

The district court entered final judgment on May 2, 2007. Axis-Shield timely appealed

the court’s decision. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).

                                      DISCUSSION

       We review a district court’s grant of summary judgment de novo, reapplying the

standard applicable at the district court. See Rodime PLC v. Seagate Tech., Inc., 174

F.3d 1294, 1301 (Fed. Cir. 1999). Summary judgment is appropriate “if the pleadings,

depositions, answers to interrogatories, and admissions on file, together with the

affidavits, if any, show that there is no genuine issue as to any material fact and that the

moving party is entitled to judgment as a matter of law.” Fed. R. Civ. P. 56(c). In

addition, in deciding a motion for summary judgment, “[t]he evidence of the nonmovant

is to be believed, and all justifiable inferences are to be drawn in his favor.” Anderson v.

Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).

       A determination of infringement requires a two-step analysis. “First, the court

determines the scope and meaning of the patent claims asserted. . . . [Second,] the

properly construed claims are compared to the allegedly infringing device.” Cybor Corp.

v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc) (citations omitted).

Step one, claim construction, is an issue of law, Markman v. Westview Instruments,

Inc., 52 F.3d 967, 970-71 (Fed. Cir. 1995) (en banc), aff’d, 517 U.S. 370 (1996), that we

review de novo, Cybor, 138 F.3d at 1456. Step two, comparison of the claim to the

accused device, requires a determination that every claim limitation or its equivalent be

found in the accused device. See Warner-Jenkinson Co. v. Hilton Davis Chem. Co.,

520 U.S. 17, 29 (1997). Those determinations are questions of fact, and on summary

2007-1349                                    8
judgment, the issue is whether there is no genuine issue of material fact regarding

infringement. Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998).

          Axis-Shield raises a myriad of arguments on appeal, not all of which need to be

treated by this court in light of the conclusions we have reached. Axis-Shield primarily

asserts that the district court erred in granting summary judgment under both

infringement theories because the court’s conclusions were premised on incorrect claim

construction.     With respect to the first summary judgment decision relating to its

HMTase infringement theory, Axis-Shield argues that the court erred in construing

“homocysteine conversion products” and thus erred in concluding that the accused

assay did not meet that claim limitation. With regard to the second summary judgment

decision relating to the SAH-hydrolase infringement theory, Axis-Shield argues that the

court erred in determining that the accused assay did not meet the “assessing” limitation

of the claims. According to Axis-Shield, the court’s error was based on incorrect claim

construction of several claim terms, including “homocysteine conversion products,”

“homocysteine converting enzyme,” and “homocysteine co-substrate.”

          In response, General Atomics defends the district court’s claim construction.

Thus, according to General Atomics, summary judgment of noninfringement was proper

because there were no genuine issues of material fact as to whether the accused assay

infringed the asserted claims and General Atomics was entitled to judgment as a matter

of law.

A.        Axis-Shield’s HMTase Infringement Theory

          We first address the district court’s grant of summary judgment that was

premised on Axis-Shield’s HMTase infringement theory. The crux of the district court’s

2007-1349                                    9
decision rested on the claim term “homocysteine conversion products.” In construing

that term, the court concluded that “homocysteine conversion products” are “those

products of the homocysteine conversion reaction that are derived from homocysteine.”

Gen. Atomics v. Axis-Shield, 440 F. Supp. 2d 1083, 1095 (N.D. Cal. 2006).             The

relevant issue on appeal with respect to that term is whether the district court correctly

concluded that a homocysteine conversion product must be derived from homocysteine.

We agree with General Atomics and the district court that it does. 3

      To determine the proper meaning of “homocysteine conversion products,” we

need do little more than to look to the language of the claims. Here, the plain language

of both independent claims supports the district court’s construction. The claims recite

that the assessed analyte is “selected from the group consisting of the homocysteine

conversion products of the enzymic conversion of homocysteine by said enzyme.” ’127

patent claim 1, ’717 patent claim 1 (emphases added). That language indicates that

the “products” are those products that result from the conversion of homocysteine.

Indeed, the latter portion of the claim limitation—“of the enzymic conversion of

homocysteine by said enzyme”—emphasizes this point by focusing solely on

homocysteine and its conversion into another compound or compounds.

      Contrary to Axis-Shield’s assertion, the language of the claim does not refer to

just any product resulting from the homocysteine conversion reaction. Had the claim

been written as “homocysteine conversion reaction products,” or “products of the

      3
          Axis-Shield does not argue that, under its HMTase infringement theory, the
accused assay is within the ’127 patent claims because the analyte that is assessed is a
homocysteine co-substrate. Therefore, our discussion with respect to Axis-Shield’s
HMTase infringement theory is confined to the construction of the “homocysteine
conversion product” limitation.
2007-1349                                   10
homocysteine conversion reaction,” Axis-Shield’s argument might be more tenable

because that might suggest that the products may be any products resulting from a

homocysteine conversion reaction. Indeed, when referencing the reaction as a whole in

the specification, the patentee used broader terms such as “homocysteine conversion

reaction” or “reaction.” See ’127 patent col.2 ll.42-45 (“The homocysteine co-substrate

assessed in the method of the invention is a compound which reacts with homocysteine

in the enzyme catalyzed . . . homocysteine conversion reaction.”) (emphasis added); id.

at col.3 ll.1-4 (“[t]he preferred homocysteine converting enzyme used according to the

invention is S-adenosyl-homocysteine hydrolase (SAH-hydrolase) which catalyses [sic]

the homocysteine reaction”) (emphasis added). However, because the plain language

of the claim refers specifically to the conversion of homocysteine when defining the

group of “products” from which an analyte may be selected, the claim as written

indicates that “products” refers to products that result from the enzymic conversion of

homocysteine, not products that otherwise result from the reaction. Such a construction

gives full meaning to every word of the entire claim term. Bicon, Inc. v. Straumann Co.,

441 F.3d 945, 950 (Fed. Cir. 2006) (“claims are interpreted with an eye toward giving

effect to all terms in the claim”). A homocysteine conversion product of the enzymic

conversion of homocysteine is a product converted from homocysteine by an enzyme.

For example, methionine is a homocysteine conversion product because it is simply

homocysteine in which a hydrogen atom has been replaced by a methyl group. It is a

modification of homocysteine. Thus, the district court’s construction, which requires the

homocysteine conversion products to be derived from the homocysteine compound, is

supported by the plain language of the claim.

2007-1349                                  11
       In addition to the clear guidance provided by the claim language, we may also

turn to the specification to determine whether the patentee attributed a different

meaning to the term. As an initial matter, we note that aside from the Abstract, which

mirrors the claim language, the term “homocysteine conversion products” does not

appear in the specification.    While the specification refers to other terms such as

“conversion products” or “products,” those references, which do not relate to

“homocysteine conversion products,” shed no light on the meaning of that claim term.

       The district court’s claim construction actually tracks the first embodiment

disclosed in the specification. In describing the invention, the specification discloses the

following homocysteine reaction which is catalyzed by the enzyme SAH-hydrolase:

                                       SAH‐hydrolase 

’127 patent col.3 ll.1-9. According to the specification, SAH-hydrolase is the preferred

homocysteine converting enzyme. The specification further discloses that the above

reaction is reversible; that is, the reaction could run in either direction. In the forward

direction, adenosine and homocysteine combine to form SAH. In the reverse reaction,

SAH hydrolyzes to form adenosine and homocysteine. Id. at col.3 ll.10-20.

       This embodiment reflects the forward direction of the reaction. Adenosine acts

as the homocysteine co-substrate, which the patent defines as “a compound which

reacts with homocysteine in the enzyme catalysed [sic], e.g., a SAH-hydrolase

catalysed [sic], homocysteine conversion reaction.” Id. at col.2 ll.42-45. SAH-hydrolase

acts as the homocysteine converting enzyme. Both adenosine and homocysteine react

in the presence of SAH-hydrolase to yield SAH—the homocysteine conversion product.

2007-1349                                   12
The specification teaches that “the amount of homocysteine in the sample can . . . be

determined from the alteration in the adenosine concentration.” Id. at col.2 ll.44-45.

Because SAH is derived from the homocysteine molecule and is the homocysteine

conversion product, the district court’s construction of “homocysteine conversion

products” reflects that embodiment.

       Axis-Shield asserts that the court’s claim construction is unduly narrow in light of

other embodiments disclosed in the specification, including the second embodiment

referred to as the inhibition embodiment.          That embodiment “take[s] particular

advantage of the fact that homocysteine acts as an inhibitor of SAH-hydrolase,

suppressing the hydrolysis reaction which forms homocysteine and adenosine and

pushing the reaction equilibrium in favour [sic] of SAH synthesis.” Id. at col.3 ll.16-20.

In that embodiment, the level of homocysteine is measured by contacting the test

sample with SAH and SAH-hydrolase. Id. at col.3 ll.48-55. As a result of the hydrolysis

reaction, SAH would break apart to form homocysteine and adenosine. Id. Because of

the inhibiting effect homocysteine has on SAH-hydrolase, however, “[a]ny homocysteine

present in the test sample will counteract this net reaction, and thus inhibit the formation

of adenosine, the amount of which is monitored.”         Id. at col.3 ll.52-55.   Thus, by

measuring the amount of remaining adenosine, the level of homocysteine can be

determined. Specifically, the amount of adenosine would be inversely proportional to

the amount of sample homocysteine. Axis-Shield argues that the district court’s claim

construction cannot be correct because it would not cover this inhibition embodiment.

In particular, Axis-Shield notes that adenosine—which is the analyte being assessed—is

neither a homocysteine conversion product because it is not derived from

2007-1349                                   13
homocysteine, nor a homocysteine co-substrate because it does not react with

homocysteine in the homocysteine conversion reaction of the assay under the court’s

construction.

      We are not persuaded by Axis-Shield’s argument. A claim need not cover all

embodiments in a patent specification. PSN Ill., LLC v. Ivoclar Vivadent, Inc., No. 2007-

1512, 2008 WL 1946550, at *5 (Fed. Cir. May 6, 2008). Prosecution strategies may

evolve so that some embodiments are covered in a patent and others are not. Here,

while it is correct that the inhibition embodiment is not covered by the asserted claims

under the district court’s claim construction because the analyte that is assessed

(adenosine) is neither a homocysteine conversion product nor a homocysteine co-

substrate, it appears from the record that that inhibition embodiment is covered by claim

17 of the ’581 patent resulting from the parent application of the patents in suit, which

was originally asserted against General Atomics but subsequently dismissed from this

case. 4 Thus, Axis-Shield’s assertion that “homocysteine conversion products” must be

      4
          Claim 17 of the ’581 patent reads as follows:

      An immunological method for indirectly assaying homocysteine in a
      sample, said method comprising the steps of:

      (a) contacting said sample with S-adenosyl homocysteine hydrolase
      enzyme and S-adenosyl homocysteine wherein said S-adenosyl
      homocysteine hydrolase converts said S-adenosyl-homocysteine into a
      non-labelled analyte wherein said non-labelled analyte is adenosine; and

      (b) determining the presence or amount of the non-labelled analyte
      without chromatographic separation by contacting said sample with an
      antibody which specifically binds with said non-labelled analyte and with a
      detectable hapten for said antibody other than said non-labelled analyte
      and wherein determining the presence or amount of said non-labelled
      analyte is effected indirectly by determining the presence or amount of
      said detectable hapten either bound or not bound to said antibody,
2007-1349                                   14
construed broadly so that the asserted claims cover the inhibition embodiment is inapt,

particularly in light of the plain language of the claim, which is both clear and

unambiguous, see Ethicon Endo-Surgery, Inc. v. U.S. Surgical Corp., 93 F.3d 1572,

1579 (Fed. Cir. 1996) (rejecting a proffered construction because “the plain meaning of

the claim [would] not bear [such] a reading”), and the coverage of this embodiment in

the parent patent.   The patentee chose to use the term “homocysteine conversion

products” in the asserted claims of the ’127 and ’717 patents, which require that the

products at issue are those that result from the conversion of homocysteine. As such,

we decline to depart from the plain meaning of the claim term by expanding the scope

of “products” to include any product resulting from the homocysteine conversion

reaction.

       Accordingly, because the analyte assessed in the accused assay is SAH, which

is a conversion product of SAM, not of homocysteine, we conclude that the court

properly granted summary judgment of noninfringement based on Axis-Shields’

HMTase infringement theory.

B.     Axis-Shield’s SAH-Hydrolase Infringement Theory

       The district court also granted summary judgment based on Axis-Shield’s SAH-

hydrolase infringement theory, in which Axis-Shield appears to assert that the accused

assay infringes the asserted claims because it allegedly uses a homocysteine

conversion enzyme, viz., SAH-hydrolase, and assesses an analyte that is either a

homocysteine co-substrate (adenosine) or a homocysteine conversion product (SAH),

       wherein the amount of the non-labelled analyte is indirectly proportional to
       the amount of homocysteine in said sample.

’581 patent claim 17 (emphases added).
2007-1349                                  15
during the latter phase of the process.         The district court rejected Axis-Shield’s

assertion. In a well-reasoned opinion, the court determined that the accused assay fails

to meet the properly-construed claim limitations because it cannot differentiate between

SAH produced from a SAH-hydrolase reaction and that from an HMTase reaction. It

therefore does not meet the “assessing a non-labelled analyte” limitation.

       In challenging the court’s decision, Axis-Shield raises several arguments in

asserting that the accused product infringes under this alternate theory. Axis-Shield

relies in part on its previous argument that the court erred in construing the term

“homocysteine conversion products.” For the reasons stated above, that argument is

rejected. Axis-Shield further argues that the court erred by improperly construing the

terms “homocysteine converting enzyme” and “homocysteine co-substrate,” and also

erred by failing to correctly apply other constructions stipulated by the parties. Having

carefully reviewed Axis-Shield’s arguments, we find no error in the court’s analysis and

conclude that Axis-Shield fails to identify any basis for reversing the court’s decision.

Accordingly, we thus affirm the court’s grant of summary judgment based on Axis-

Shield’s alternate theory.

       We have considered all of the remaining arguments Axis-Shield has raised in its

briefs with regard to its theories of infringement and find them unpersuasive.

2007-1349                                  16
                                       CONCLUSION

       For the foregoing reasons, the district court correctly construed the relevant

disputed terms, properly applied the stipulated claim construction, and appropriately

granted summary judgment of noninfringement in favor of General Atomics.         The

decision of the district court is therefore affirmed.

                                         AFFIRMED

2007-1349                                     17