RADER, Circuit Judge.
Following a bench trial, the United States District Court for the Northern District of Illinois determined that the pa-roxetine hydrochloride anhydrate product produced by Apotex Corp., Apotex, Inc., and TorPharm, Inc. (collectively Apotex) will not infringe claim 1 of U.S. Patent No. 4,721,723 owned by SmithKline Beecham Corp. and Beecham Group, P.L.C. (collectively SmithKline). SmithKline Beecham Corp. v. Apotex Corp., 247 F.Supp.2d 1011, 1052 (N.D.Ill.2003). Claim 1 of the '723 patent recites, in its entirety, “Crystalline paroxetine hydrochloride hemihydrate.” Upon this court’s revision of the trial court’s erroneous claim construction, Apo-tex’s product will infringe this claim. Nonetheless because the public use bar of 35 U.S.C. § 102(b) renders claim 1 of the '723 patent invalid, this court affirms the district court’s judgment in favor of Apo-tex.
I.
In the late 1970s, a British company called Ferrosan invented a new class of compounds, including a compound that became known as paroxetine. See U.S. Patent No. 4,007,196. The '196 patent claims paroxetine and its salts and discloses their antidepressant properties. Ferrosan eventually developed a process to produce the crystalline hydrochloride salt of parox-etine, or paroxetine hydrochloride (PHC). In 1980, Ferrosan licensed the '196 patent [1309]*1309and its other PHC-related technology to SmithKline. SmithKline began manufacturing PHC in its Harlow plant in England.
In March 1985, a chemist in Smith-Kline’s Worthing, England laboratory, Alan Curzons, created a new crystalline form of PHC while attempting to improve PHC production. Curzons’ test results established that the new product was the hemihydrous form of PHC (PHC hemihyd-rate), while Ferrosan’s original form was anhydrous PHC (PHC anhydrate). PHC anhydrate comprises crystals of PHC without bound water molecules. PHC hemih-ydrate comprises PHC crystals with one bound water molecule for every two PHC molecules. PHC hemihydrate proved more stable and thus more easily packaged and preserved.
Further review of the SmithKline samples showed that the Harlow plant had unwittingly made PHC hemihydrate as early as December 1984. In May 1985, SmithKline began double-blind clinical tests in the United States to determine the safety and efficacy of PHC hemihydrate capsules to treat depression symptoms. In these clinical tests, the doctors and patients were aware of the drug being tested, but were not aware which patients were taking a placebo and which were taking the actual drug.
SmithKline filed a patent application in the British Patent Office on October 25, 1985 relating to “crystalline paroxetine hydrochloride, its preparation and its uses as a therapeutic agent.” The British application identified the invention as both the hemihydrate and the anhydrate form of PHC, as well as mixtures that contain a major portion of either form. One year later, on October 23,1986, SmithKline filed a U.S. application claiming priority to the British application that issued as the '723 patent in 1988. The '723 patent does not claim PHC anhydrate and does not claim mixtures of the two PHC forms. The only claim at issue in this case is claim 1, which reads, “Crystalline paroxetine hydrochloride hemihydrate.”
In 1993, after completing the necessary FDA approval process, SmithKline placed its antidepressant drug with PHC hemih-ydrate as the active ingredient on the market under the name Paxil®. In 1998, TorPharm, Inc., an Apotex affiliate and manufacturer of Apotex’s generic antidepressant, filed an Abbreviated New Drug Application (ANDA) with the FDA, under 21 U.S.C. § 355(j), seeking approval to market its own PHC antidepressant drug. Apotex identified the active ingredient in its antidepressant as PHC anhydrate. Apotex’s ANDA included a paragraph IV certification, see 21 U.S.C. § 355(j)(2)(A)(IV), that indicated Apotex intended to market the drug before the expiration of the '723 patent because its drug would not infringe that patent.
In 1998, SmithKline initiated this infringement action against Apotex under 35 U.S.C. § 271(e)(2) on the basis of Apotex’s ANDA filing. SmithKline alleges that Apotex’s proposed drug will infringe claim 1 of the '723 patent. SmithKline does not allege that claim 1 of the '723 patent covers PHC anhydrate. After all, PHC an-hydrate — the Ferrosan discovery — is prior art for the '723 patent. SmithKline asserts that Apotex will infringe by manufacturing PHC anhydrate tablets that necessarily contain, by a conversion process discussed below, at least trace amounts of PHC hemihydrate.
The parties filed various summary judgment motions, including cross motions for summary judgment that claim 1 of the '723 patent was invalid (or valid) under 35 U.S.C. § 102(b) for an impermissible public use. The § 102(b) motions acknowledged that the clinical trials occurred more than one year before SmithKline’s filing [1310]*1310date for the '723 patent, but disputed whether those tests qualified for the experimental use negation. The district court denied Apotex’s motion and granted SmithKline’s motion, holding that the '723 patent was not invalid for public use under § 102(b). The district court reasoned that the clinical trials qualified as experimental uses. See SmithKline Beecham Corp. v. Apotex Corp., 286 F.Supp.2d 925, 932-38 (N.D.Ill.2001).
The district court then held a bench trial to determine the proper interpretation of claim 1 and resolve the remaining infringement and validity issues. On the question of claim construction, the district court limited claim 1 to PHC hemihydrate in commercially significant amounts. SmithKline Beecham Corp., 247 F.Supp.2d at 1030. The trial record contained uncontested testimony that a PHC anhydrate-hemihydrate mixture would need to possess a percentage of PHC hemihydrate in the “high double digits” if the hemihydrate component were to contribute any commercial value. Id. The district court grafted that commercial significance into the claim and held that Apotex’s proposed PHC drug will not infringe claim 1 of the '723 patent. The district court found, as a factual matter, that Apotex’s PHC anhyd-rate tablets will not contain detectable or commercially significant amounts of PHC anhydrate and rejected SmithKline’s evidence to the contrary. Id. at 1031-39. The trial court also determined that claim 1 is not invalid.
SmithKline contested the district court’s claim interpretation noting that claim 1 is clear on its face and encompasses PHC hemihydrate in any amount, however small or insignificant. In rejecting that proposed claim interpretation, the district court also opined that SmithKline’s proposed construction would render claim 1 indefinite. The district court reasoned that SmithKline’s interpretation would place potential infringers in the untenable position of never knowing whether their product infringes because even a single undetectable crystal of PHC hemihydrate would infringe. Id. at 1029-30.
To show that manufacture of PHC an-hydrate tablets necessarily creates PHC hemihydrate, SmithKline proffered expert testimony on the so-called “seeding” or “disappearing polymorph” theory. Under this theory, Ferrosan may have originally created a crystalline compound, namely PHC anhydrate, in a relatively unstable form. As Ferrosan and its successors improved the manufacturing and testing procedures for PHC, the compound “morphed” into a more pure and stable form, namely the PHC hemihydrate discovered in SmithKline’s facilities. Once this new form or polymorph exists, Smith-Kline’s experts explained, the general environment becomes “seeded” with crystals of the new polymorph. In this seeded environment, the old polymorph converts to the new polymorph upon its inevitable contact with seeds of the new polymorph. In other words, the creation of a pure version of the old polymorph becomes extremely difficult, if not impossible; the old poly-morph has effectively disappeared and been replaced by the new.
SmithKline’s experts applied the disappearing polymorph theory to show that Apotex’s PHC anhydrate tablets inevitably convert to hemihydrate when combined with moisture, pressure, and practically ubiquitous PHC hemihydrate seeds. The district court found that SmithKline’s evidence on seeding and the disappearing polymorph theory supported the inference that Apotex’s PHC anhydrate .tablets will contain at least trace, or undetectable, amounts of PHC hemihydrate. Id. at 1042-43. Thus, under SmithKline’s claim construction, the district court held that [1311]*1311Apotex’s PHC anhydrate drug would infringe claim 1 of the '723 patent. Id.
Alternatively, if claim 1 was construed to cover any amount of PHC hemihydrate and was, therefore, infringed, the district court purported to create a new equitable defense to infringement in favor of Apotex. Id. at 1043-45. Under this new defense, SmithKline was responsible for producing the hemihydrate, which, by virtue of SmithKline’s disappearing polymorph theory, seeded the environment. Consequently, SmithKline caused the alleged infringement. The district court reasoned that Apotex should enjoy the right to practice the prior art by manufacturing PHC anhydrate. Accordingly, under its alternative equitable defense, the district court absolved Apotex of liability for the consequences of SmithKline’s own conduct that rendered the practice of the prior art impossible without infringing the '723 patent. The district court also held that its inherent equitable powers and the equitable nature of injunctions in general placed the injunction mandated by 35 U.S.C. § 271(e)(4)(A) within the discretion of the district court. Id. at 1045-52.
SmithKline also sought to assert a claim of induced infringement against Apotex on the theory that anhydrate tablets convert to PHC hemihydrate in the stomach of a patient due to the increased humidity and pressure. The district court excluded SmithKline’s evidence on this issue, finding that SmithKline would likely not meet its burden of showing “gastrointestinal infringement.” Id. at 1014-15. Finally, the district court considered other alternative claim constructions, which would allow claim 1 to cover PHC hemihydrate in amounts detectable either by methods available at the time the '723 patent was filed or by any means that later became available. Id. at 1052. The record shows that SmithKline presented the results of tests on various samples of Apotex tablets. These tests showed PHC hemihydrate in the Apotex product. The district court rejected this evidence as unreliable, mainly because SmithKline’s counsel excluded select tablets from the testing without reasonable explanation. Id. at 1032-42. The trial court found these excluded tablets to represent best the product Apotex would manufacture upon ANDA approval. Id. Accordingly, the district court held that SmithKline did not prove that Apotex’s tablets will contain any detectable amount of PHC hemihydrate.
SmithKline presents five arguments on appeal. First, the district court erred in limiting claim 1 to commercially significant amounts of PHC hemihydrate. Second, contrary to the trial court’s ruling, a claim construction that covers PHC hemihydrate in any amount does not render claim 1 indefinite. Third, the district court erred in creating an equitable defense to infringement based on SmithKline’s contribution to causing the infringement. Fourth, the district court erred in holding that the injunctive relief required under 35 U.S.C. § 271(e)(4) is within the district court’s discretion. Fifth, the district court abused its discretion in excluding Smith-Kline’s evidence of induced infringement.
In its cross-appeal, Apotex argues that the district court erred in granting summary judgment that SmithKline’s clinical tests qualified as an experimental use. In particular, Apotex asserts that claim 1 of the '723 patent is invalid for public use under 35 U.S.C. § 102(b) as a matter of law. This court has jurisdiction over these appeals under 28 U.S.C. § 1295(a)(1).
II.
Standards of Review
This court reviews summary judgments without deference. See Beech Aircraft Corp. v. EDO Corp., 990 F.2d 1237, 1245 [1312]*1312(Fed.Cir.1993). Of course, a denial of summary judgment, by itself, is not a final judgment amenable to appeal like a grant of summary judgment. However, when both parties move for summary judgment, each motion “must be independently assessed on its own merit.” California v. United States, 271 F.3d 1377, 1380 (Fed.Cir.2001). In such circumstances, this court determines whether summary judgment is appropriate under the standard rules of Fed.R.Civ.P. 56.
In this case, both parties sought summary judgment; the district court granted one and denied the other. Thus, the record may show that the parties have conceded, and the district court has found, that no material factual issues remain in dispute. See Beech Aircraft, 990 F.2d at 1245. If this court determines that no material facts remain in dispute, it may proceed to determine entitlement to judgment under the law. See Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 962 (Fed.Cir.2001) (“[Rjeversal is required if the district court ‘engaged in a faulty legal analysis in applying the law to the facts and a correct application of the law to those facts might bring a different result.’ ”) (quoting Litton Indus. Prods., Inc. v. Solid State Sys. Corp., 755 F.2d 158, 164 (Fed.Cir.1985)); see also Anderson v. Liberty Lobby Inc., 477 U.S. 242, 248, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986).
This court reviews a district court’s judgment, following a bench trial, for errors of law or clearly erroneous findings of fact. See Allen Eng’g Corp. v. Bartell Indus., Inc., 299 F.3d 1336, 1343-44 (Fed.Cir.2002). Patent infringement proceeds under a two-step analysis. First, the court interprets the claims to determine their proper scope and meaning. See Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed.Cir.1998) (en banc). Next, the court measures the accused product or process against the standard of the properly interpreted claims. Id.
This court reviews claim construction without deference. See Markman v. Westview Instruments, Inc., 52 F.3d 967, 979, (Fed.Cir.1995) (en banc), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996). This court reviews the second step, measurement of the accused product or process against the claim, as a question of fact. See Allen Eng’g, 299 F.3d at 1343—44; Gen. Mills, Inc. v. Hunt-Wesson, Inc., 103 F.3d 978, 981 (Fed.Cir.1997). The review of indefiniteness under 35 U.S.C. § 112, paragraph 2, proceeds as a question of law without deference. See Solomon v. Kimberly-Clark Corp., 216 F.3d 1372, 1377 (Fed.Cir.2000); Personalized Media Communications, LLC v. Int’l Trade Comm’n, 161 F.3d 696, 702 (Fed.Cir.1998).
Factual Findings
As an initial matter, this court holds that the record supports the district court’s factual findings. In particular, the district court did not clearly err in concluding that Apotex’s PHC anhydrate product will include trace amounts of PHC hemihydrate based on the record evidence of seeding and disappearing polymorphs. See SmithKline Beecham Corp., 247 F.Supp.2d at 1019-23.
The district court also did not clearly err in finding that Apotex’s anhydrate product will not contain detectable quantities of PHC hemihydrate because SmithKline selectively tested the Apotex samples without explaining its reasons for excluding some Apotex products from the examination. Specifically, the district court’s discretionary exclusion of Smith-Kline’s unreliable evidence on this issue does not render the subsequent factual finding clearly erroneous. Accordingly, this court decides the legal issues in this [1313]*1313appeal against the factual background as determined by the district court.
Claim Construction & Indefiniteness
Claim interpretation requires the court to ascertain the meaning of the claim to one of ordinary skill in the art at the time of invention. ResQNet.com, Inc. v. Lansa, Inc., 346 F.3d 1374, 1378 (Fed.Cir.2003); Phillips Petroleum Co. v. Huntsman Polymers Corp., 157 F.3d 866, 871 (Fed.Cir.1998). This task requires the court to place the claim language in its proper technological and temporal context. The best tools for this enterprise are the various forms of intrinsic evidence and, when appropriate, extrinsic evidence. See Vitronics, Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996). The intrinsic evidence, “i.e., the patent itself, including the claims, the specification and, if in evidence, the prosecution history ... is the most significant source of the legally operative meaning of disputed claim language.” Id,
Of course, at all times, the language of the claims governs their scope and meaning. See Dow Chem. Co. v. Sumitomo Chem. Co., 257 F.3d 1364, 1372 (Fed.Cir.2001). Unless the intrinsic evidence compels a contrary conclusion, the claim language carries the meaning accorded those words in the usage of skilled artisans at the time of invention. See id.; Vitronics, 90 F.3d at 1582.
As stated earlier, claim 1 of the '723 patent reads, “Crystalline paroxetine hydrochloride hemihydrate.” This language is not ambiguous, but rather describes á very specific compound. The record repeatedly shows that artisans in this area of technology at the time of invention would have understood that the claim embraces PHC hemihydrate without further limitation.
The inquiry proceeds to the remainder of the intrinsic record to determine if the patent applicant gave these unambiguous words some unexpected definition. The district court limited claim 1 to commercially significant amounts of PHC hemih-ydrate. The trial court found support for this limitation in portions of the '723 patent that discuss the pharmaceutical and commercial properties of PHC hemihyd-rate. For example, the specification discusses the superior handling properties of the hemihydrate form that improve the manufacture of PHC. Those references, however, do not redefine the compound in terms of its commercial properties, but emphasize that the new compound exhibits favorable characteristics. A description of characteristics does not redefine a compound with an established and unambiguous structural definition.
Moreover, nothing in the '723 patent limits that structural compound to its commercial embodiments. Rather, the '723 specification discloses PHC hemihydrate as a compound without reference to its commercial applications. For example, the specification states that the “present invention provides crystalline parqxetine hydrochloride hemihydrate as a novel compound.” '723 patent, col. 1, 11. 57-58. Furthermore, nothing in the prosecution history of the '723 patent defines the invention in terms of commercially significant quantities. Thus, reading claim 1 in the context of the intrinsic evidence, the conclusion is inescapable that the claim encompasses, without limitation, PHC hem-ihydrate — a crystal form of paroxetine hydrochloride that contains one molecule of bound water for every two molecules of paroxetine hydrochloride in the crystal structure.
The district court openly discussed the policies that led to its insertion of commercially significant quantities as a limitation on the meaning of the claimed compound. The district court observed that a claim construction that covers trace [1314]*1314amounts of PHC hemihydrate would likely preclude attempts to make the prior art PHC anhydrate compound. After explaining the. “in terrorem effect” of such a “broad” claim construction, the district court rejected the literal scope of claim 1 because it would produce “absurd results” and would “not serve any policy of patent law.” Claim construction, however, is not a policy-driven inquiry. As stated earlier, it is a contextual interpretation of language. The scope of patent claims can neither be broadened nor narrowed based on abstract policy considerations regarding the effect of a particular claim meaning. See Quantum Corp. v. Rodime, PLC, 65 F.3d 1577, 1584 (Fed.Cir.1995) (“[I]t is well settled that no matter how great the temptations of fairness or policy making, courts do not redraft claims”). For this precise reason, this court has repeatedly stated that a court must construe claims without considering the implications of covering a particular product or process. See Neo-Magic Corp. v. Trident Microsys. Inc., 287 F.3d 1062, 1074 (Fed.Cir.2002); SRI Int'l. v. Matsushita Elec. Corp., 775 F.2d 1107, 1118 (Fed.Cir.1985).
The district court also justified its commercial-significance limitation to preserve the claim’s validity in the face of a challenge to its definiteness under § 112, second paragraph. In essence, the district court considered the claim indefinite if construed to cover undetectable trace amounts of the PHC compound. In other words, the trial court feared that potential infringers would not be able to determine (and avoid) infringement if they cannot detect the claimed compound. See Morton Int’l, Inc. v. Cardinal Chem. Co., 5 F.3d 1464, 1469-70 (Fed.Cir.1993). This reasoning misses the proper purpose of the definiteness requirement.
The second paragraph of § 112 requires the specification of a patent to “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” 35 U.S.C. § 112, ¶ 2 (2000). To satisfy this requirement, the claim, read in light of the specification, must apprise those skilled in the art of the scope of the claim. See Miles Labs., Inc. v. Shandon, Inc., 997 F.2d 870, 875 (Fed.Cir.1993). Moreover, claims need not “be plain on their face in order to avoid condemnation for indefiniteness; rather, what [this court has] asked is that the claims be amenable to construction, however difficult that task may be.” Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed.Cir.2001). In this case, the claim covers a definite chemical structure. To a chemist in this field, this claim is plain on its face. Thus, claim 1 of the '723 patent' cannot be invalid for indefiniteness under § 112.
In Morton, this court affirmed a district court’s judgment of indefiniteness because “one skilled in the art could not determine whether a given compound was within the scope of the claims.” Morton, 5 F.3d at 1470. Thus, the claims at issue were “not sufficiently precise to permit a potential competitor to determine whether or not he is infringing.” Id. The Morton case, therefore, does not hold that the inability to detect the claimed compound in the infringing device renders a compound claim indefinite. Rather, Morton stands for the unremarkable proposition that a compound claim, to be definite, must apprise a skilled artisan of the bounds of the claim. The record in Morton contained “considerable evidence showing that those skilled in the art could not make the claimed compounds using the procedures of the specification, and no evidence that such compounds even exist.” Id. at 1469-70.
This case bears little similarity to Morton. In this case, claim 1 unambiguously [1315]*1315identifies the bounds of the claim. It states “Crystalline paroxetine hydrochloride hemihydrate.” Thus, this claim recites in clear terms a discernible chemical structure. It would be difficult to imagine a more clear and definite claim.
The test for indefiniteness does not depend on a potential infringer’s ability to ascertain the nature of its own accused product to determine infringement, but instead on whether the claim delineates to a skilled artisan the bounds of the invention. In this case, the problem for Apotex is that it cannot accurately ascertain the nature of its own product. The scope of this claim is clear; the infringement of the Apotex product is not. Even if a claim is broad enough to embrace undetectable trace amounts of the claimed invention, “[bjreadth is not indefiniteness.” In re Gardner, 57 C.C.P.A. 1207, 427 F.2d 786, 788 (CCPA 1970). Stated more precisely, this claim is neither broad nor narrow, but definitive of this particular chemical structure. For inventing and disclosing this structure, the inventor enjoys the exclusive right to practice that invention for the patent’s limited term. Accordingly, claim 1, as construed above, is not indefinite under 35 U.S.C. § 112, second paragraph.
Infringement and Equity
Having interpreted claim 1 to cover PHC hemihydrate without further limitation, this court turns to infringement. In anticipation of this very scenario, the district court performed a factual infringement analysis based on this correct claim construction. The district court held that the evidence showed that Apotex’s PHC anhydrate tablets would contain trace amounts of PHC hemihydrate. As indicated above, the record supports this factual finding. This court, therefore, affirms the district court’s finding that Apotex’s product will infringe under this court’s claim construction.
Because Apotex seeks to practice- the prior art, and because that practice infringes, the next logical inquiry involves anticipation. That is, if the prior art infringes now, logically the prior art should have anticipated the claim before the filing of the '728 patent. See Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc., 246 F.3d 1368, 1378 (Fed.Cir.2001) (restating the axiom that “that which would literally infringe if later in time anticipates if éarlier”). At trial, Apotex asserted that Ferro-san’s process of making PHC anhydrate inherently resulted in trace amounts of the hemihydrate prior to the '723 patent and thus anticipated that patent. The district court, however, determined that Apotex did not present clear and convincing evidence of inherent anticipation. According to the district court’s findings, “no one knows when the hemihydrate form of pa-roxetine came into existence, although it is a reasonable inference that it did not exist in a detectable amount until” SmithKline’s “serendipitous” discovery. SmithKline Beecham Corp., 247 F.Supp.2d at 1022, 1025. Apotex does not appeal that ruling.
SmithKline’s disappearing polymorph theory makes its apparently inconsistent positions possible. ■ On the one hand, SmithKline asserts that the creation of a prior art compound will result in a product containing at least trace amounts of their patented compound. On the other hand, SmithKline contends that the creation of the prior art compound before Smith-Kline’s discovery of its compound did not have the same result. For this reason, the district court was understandably uncomfortable about allowing, claim 1 to embrace its literal scope. The district court feared such a construction would result in “a considerable extension in the. effective patent term of paroxetine because it- might be[1316]*1316come difficult or even impossible to manufacture the pure anhydrous form after the Ferrosan patent expired.” Id. at 1019. While these concerns are certainly legitimate, claim construction, as noted before, proceeds independent of its policy implications. Fortunately, the district court had the foresight to consider alternative analy-ses in this unique situation.
The district court, in its alternative infringement analysis, properly found infringement, but cabined the infringement with a new equitable defense. In short, the defense would apply where the paten-tee significantly contributed to causing the infringement. After all, SmithKline’s creation of the hemihydrate form of PHC also created a seeded environment that, under the facts found by this district court, makes the practice of the prior art an infringement, while precluding operation of anticipation by inherency. In this unique and unprecedented circumstance, the trial court understandably reached out to find an equitable remedy to protect Apotex. In any event, notwithstanding the potential merit of a new equitable doctrine in this unprecedented instance, this court can resolve this case without its application because claim 1 is invalid for public use under 35 U.S.C. § 102(b). Accordingly, this court declines to address the trial court’s proposed equitable defense.
The concurring opinion seeks to remedy the perceived inequity in this case by applying 35 U.S.C. § 101, arguing the subject matter of claim 1 does not cover patentable subject matter. Unfortunately, the concurrence confuses patent eligibility under § 101 with patentability under other provisions in the Patent Act, such as 35 U.S.C. § 102. The concurrence admits that PHC hemihydrate is a synthetic, man-made compound eligible for patent protection. In fact, the claimed invention is without question a “composition of matter” or an article of “manufacture” within the terms of § 101. Accordingly, the claimed invention represents subject matter eligible for patent protection under § 101. With that conclusion, the inquiry under § 101 ends.
The concurring opinion, however, would expand the subject matter eligibility analysis under § 101 to encompass some review of the scope of the claims. To the contrary, “[ejither the subject matter falls within Section 101 or it does not.” Animal Legal Def. Fund v. Quigg, 932 F.2d 920, 930 (Fed.Cir.1991). The scope of the claims is not relevant to subject matter eligibility. Subject matter does not take on a different eligibility status with adjustments in the scope of the proposed claim. Patent eligibility under § 101 is simply not an issue in this case.
Public use— § 102(b)
A patent claim is not valid if “the invention was ... in public use ... in this country, more than one year prior to the date of the application for patent in the United States.” 35 U.S.C. § 102(b) (2000). Whether a patent is invalid due to public use under § 102(b) is a question of law based on underlying questions of fact. See 3M Co. v. Chemque, Inc., 303 F.3d 1294, 1301 (Fed.Cir.2002). Thus, without genuine factual disputes underlying the public use inquiry, the issue is ripe for judgment as a matter of law.
In Pfaff v. Wells Electronics, Inc., 525 U.S. 55, 119 S.Ct. 304, 142 L.Ed.2d 261 (1998), the Supreme Court rejected the former “substantially complete under a totality of circumstances” test for the on sale bar under § 102(b) and adopted a two-prong test. That test bars a patent when the claimed invention, before the critical date, was the subject of a commercial offer for sale and was ready for patenting. Id. at 67, 119 S.Ct. 304. A similar analysis applies to the public use bar under § 102(b). Although the commercial sale [1317]*1317prong is inapplicable, “[p]ublic use under 35 U.S.C. § 102(b) includes any use of the claimed invention by a person other than the inventor who is under no limitation, restriction or obligation of secrecy to the inventor.” Netscape Communications Corp. v. Konrad, 295 F.3d 1315, 1321 (Fed.Cir.2002) (emphasis added). Thus, § 102(b) erects a bar where, before the critical date, the invention was ready for patenting and was used by a person other than the inventor who is under no confidentiality obligation.
“Experimental use negates public use; when proved, it may show that particular acts, even if apparently public in a colloquial sense, do not constitute a public use within the meaning of section 102.” Baxter Int’l, Inc. v. Cobe Labs., Inc., 88 F.3d 1054, 1059 (Fed.Cir.1996) (citing TP Labs., Inc. v. Prof'l Positioners, Inc., 724 F.2d 965, 971 (Fed.Cir.1984)); see also City of Elizabeth v. Am. Nicholson Pavement Co., 97 U.S. 126, 134, 24 L.Ed. 1000 (1877). The experimental use doctrine is not an “exception” to the public use bar because it does not shift the burden of proof from the accused infringer to the patentee. Rather, it operates to negate application of the public use bar. See EZ Dock, Inc. v. Schafer Sys., Inc., 276 F.3d 1347, 1351-52 (Fed.Cir.2002) (“This court has repeatedly stressed that evidence of experimental use does not give rise to a free-standing doctrinal exception to statutory bars, but instead operates to negate application of section 102(b)”).
In other words, once the challenger of the patent has proven by clear and convincing evidence that the invention was in public use before the critical date, the burden of production shifts to the patentee to provide sufficient evidence to create a genuine issue of material fact that the use qualifies as experimental. The ultimate burden, however, remains on the challenger to prove by clear and convincing evidence that the non-experimental use was public under § 102(b). Id.
With these burdens and legal standards in mind, this court agrees with the district court and the parties that no material facts relating to the public use bar are in dispute. The record shows that PHC hemih-ydrate was in public use before the critical date of the '723 patent. Specifically, SmithKline placed PHC hemihydrate in public clinical trials in the United States in May 1985. . The critical date under § 102(b) for the '723 patent is October 23, 1985. Moreover, SmithKline administered PHC hemihydrate to patients without any apparent confidentiality restrictions, on the patients or the administering physicians. SmithKline does not question the public disclosure of its clinical trials. Rather, SmithKline asserts that the clinical trials constitute an experimental use negating the apparent public use. In SmithKline’s own words, the purpose of the clinical trials was “to establish that [PHC hemihyd-rate] actually worked (and was safe) as an antidepressant.”
Taking the facts in the light most favorable to SmithKline, this court assumes that the clinical trials were subject to satisfactory controls and otherwise properly conducted to fulfill their intended purpose — namely, to establish the efficacy and safety of PHC hemihydrate as an antidepressant drug for humans. The determinative inquiry in this case is whether SmithKline tested the invention of the asserted claim. “[T]esting or experimentation performed with respect to non-claimed features of the device does not show that the invention was the subject of experimentation.” W. Marine Elecs., Inc. v. Furuno Elec. Co., 764 F.2d 840, 847 (Fed.Cir.1985). In other words, an experimental use only negates a statutory bar when the inventor was testing claimed features of the invention. In re Theis, 610 F.2d 786, [1318]*1318793 (CCPA 1979) (“It is settled law that ... [an] experimental sale ... does not apply to experiments performed with respect to non-claimed features of an invention.”); LaBounty Mfg. Inc. v. U.S. Int’l Trade Comm'n., 958 F.2d 1066, 1074 (Fed.Cir.1992); In re Brigance, 792 F.2d 1103, 1109 (Fed.Cir.1986).
Indeed the Supreme Court case that created the experimental use negation, City of Elizabeth, 97 U.S. at 126, acknowledged the purpose of this doctrine: “The use of an invention by the inventor himself, or of any other person under his direction, by way of experiment, and in order to bring the invention to perfection, has never been regarded as such a [public] use.” In other words, the doctrine extends to experimentation on the claimed invention to bring it to perfection. The negation does not extend beyond the claimed invention or beyond the purpose of perfecting the invention. See, e.g., In re Smith, 714 F.2d 1127 (Fed.Cir.1983) (“[Experimental use ... does not include market testing”).
This court has already defined the invention of claim 1 as the PHC hemihydrate compound without further limitation regarding efficacy, commercial use, or pharmaceutical viability. SmithKline itself espouses that proper claim construction. With that definition of the invention in mind, however, clinical trials designed to establish the efficacy and safety of the compound as an antidepressant for FDA approval are not experimental uses of that claimed invention. In other words, the claim covers the compound regardless of its use as an antidepressant. The antidepressant properties of the compound are simply not claimed features. Consequently, the clinical tests, which measured the efficacy and safety of the compound as an antidepressant, did not involve the claimed features of the invention. The 1985 clinical tests, therefore, do not qualify as an experimental use to negate the statutory bar.
In making this ruling, this court is aware of cases that acknowledged an experimental use negation when the testing did not focus on an expressly claimed feature. See EZ Dock, 276 F.3d at 1353; Seal-Flex, Inc. v. Athletic Track & Court Constr., 98 F.3d 1318, 1320, 1324 (Fed.Cir.1996); Manville Sales Corp. v. Paramount Sys., Inc., 917 F.2d 544, 550-51 (Fed.Cir.1990). To some extent, this apparent confusion arises from a separate requirement of patent law to test an invention for utility, i.e., to show that it works for its intended purpose. See Scott v. Finney, 34 F.3d 1058, 1061 (Fed.Cir.1994). This court has noted the potential overlap of utility and experimental use testing. EZ Dock, 276 F.3d at 1352. As suggested by their different origins and purposes, however, utility testing (reduction to practice) and experimental use testing are not synonymous.
Testing to reduce an invention to practice shows completion of an invention and establishes its utility. See, e.g., Holmwood v. Sugavanam, 948 F.2d 1236 (Fed.Cir.1991). The focus is on whether the totality of the testing at the relevant time period was sufficient to prove an actual reduction to practice of the invention. See Scott, 34 F.3d at 1061-62. Experimental testing, on the other hand, negates evidence that an inventor has fatally postponed filing beyond a bar date. See City of Elizabeth, 97 U.S. at 126. Here, the focus is on whether the specific testing in question was necessary to reduce the claimed invention to practice. That is, after the invention is reduced to practice, further testing will not qualify as experimental use for purposes of negating a bar under § 102(b). See Continental Plastic Containers v. Owens Brockway Plastic Prods., 141 F.3d 1073, 1079 (Fed.Cir.1998) (“The policy behind experimental use negation is to give the inventor [1319]*1319an opportunity to reduce the invention to practice.... Thus, experimental use can not occur after a reduction to practice”) (citations omitted).
Due to these different origins and purposes, the narrower experimental use negation does not extend beyond perfecting claimed features. In any event, even the cases above that acknowledge experimentation on features beyond those expressly claimed remain faithful to these strict limits of the experimental use negation. Each of those cases permitted testing to negate the bar when the experimentation improves or verifies a feature inherent in the express claims of the invention.
In Manville, for example, the claimed invention covered a light pole for highways that maintenance workers could lower for repairs. See 917 F.2d at 547-48. At the outset, this court decided Manville on the basis that the applicant retained the invention confidential and at no time placed it in the public domain. Id. The purported experimental use tested the illuminating device under severe weather conditions. Neither party asserted that this experimentation exceeded the literal scope of the claims, probably because the use occurred in a remote Wyoming rest area not yet open to the public at the top of a 150-foot pole. Indeed this court noted: “Manville did nothing to lead the public to believe that its iris arm invention was in ‘the public domain.’” Manville, 917 F.2d at 549. In other words, the use was either not public or properly confidential. This court also noted: “Manville marked its design drawing with a confidentiality notice.” Id. To the limited extent that this case also relied on the experimental use negation, this court explained: “[Djurability in an outdoor environment is inherent to the purpose of the invention.” Id. at 551. Thus, the experimentation verified features inherent in the claimed invention.
In Seal-Flex, the claimed invention covered an all-weather activity mat (or track). Seal-Flex, 98 F.3d at 1320-21. The paten-tee alleged that the product it sold was not the completed invention because it was still being tested for its performance in harsh weather conditions. Id. At the outset, it is significant to note that this court decided Seal-Flex under standards for public use overruled by Pfaff. Therefore, this court weighed a “totality of circumstances” that no longer apply. Id. at 1322-23. Again, the parties did not raise the issue of limiting testing to claimed features. Like the Manville case, however, the scope of the claimed invention in Sealr-Flex carried the inherent implication of performance in severe weather conditions. It was an all-weather track. Id. at 1324. Thus, the experimentation again focused on features inherent to the claimed invention. Importantly, this court in Seal-Flex did not affirmatively find that there was no on-sale bar under § 102(b) or that the activities constituted an experimental use. Rather, this court vacated the district court’s summary judgment and remanded the case. Id.
In EZ Dock, the claim covered a “floating dock.” EZ Dock, 276 F.3d at 1348. The testing involved the dock’s performance in rough, choppy water. Id. at 1353. Although the claim did not have an express “choppy water” limitation, the claim language “floating dock” carried the implication that the invention must perform in rough water. Thus, again, the experimentation verified or improved a feature inherent to the claimed invention. Again, the court vacated the summary judgment of invalidity and remanded for determination of the on-sale bar and experimental use issues. Id. at 1353-54. In sum, this court has remained faithful to the strict requirements of the experimental use negation by limiting it to testing to perfect claimed features, or, in a few instances, testing to [1320]*1320perfect features inherent to the claimed invention. •
In this ease, SmithKline’s experimentation does not fit within the rule limiting the negation to tests on claimed features. See In re Theis, 610 F.2d at 793. In connection with the claim interpretation issue, SmithKline strenuously argues that nothing in the claim language, the specification, or the prosecution history indicates that the scope of claim 1 implicates any intended commercial significance or medical purpose. In fact, the claim does not carry any implication of commercial significance or medical purpose. While Smith-Kline benefits from the breadth of the meaning of its claim, that claim does not require testing tailored to ascertain the safety and effectiveness of a particular use. Thus, testing the medical efficacy and viability of PHC hemihydrate is not testing the claimed features of the structural invention in claim 1.
SmithKline’s assertion that the clinical tests constituted an experimental use of the invention of claim 1 is inconsistent with its claim construction position. This court also notes that these same clinical trials may serve to negate a public use bar with regard to the inventions claimed in the more specific claims of the '723 patent. Only claim 1, however, is before the court in this appeal. Nothing in the language of claim 1 can reasonably be read to carry an implication that the claimed compound will be used as an anti-depressant, or even a pharmaceutical for that matter. Because claim 1 covers the compound without further limitation, the invention of claim 1 was reduced to practice when that compound was first manufactured. Its efficacy as an anti-depressant is irrelevant to that determination.
Accordingly, a patentee should understand that testing the properties, uses, and commercial significance of a compound claimed solely in structural terms may start the clock under § 102(b) for filing a claim that is not limited by any property, commercially significant amount, or other use of the compound. Because these clinical trials tested only the safety and efficacy of PHC hemihydrate as an antidepressant, those trials were not an experimental use of the invention in claim 1. Consequently, this court determines that claim 1 of the '723 patent is invalid for public use under § 102(b) as a matter of law. This court reverses the district court’s grant of summary judgment of validity in favor of SmithKline and reverses the district court’s denial of summary judgment of invalidity in favor of Apotex.
Miscellaneous Issues
SmithKline also appealed the district court’s decision to prevent SmithKline from pursuing its contributory infringement claim. In essence, that claim asserted that the ingestion of Apotex’s PHC anhydrate tablet by a patient would result in conversion to the hemihydrate. In the interim, this court decided Schering Corp. v. Geneva Pharmaceuticals, Inc., 339 F.3d 1373 (Fed.Cir.2003). In that case, this court determined that a compound claim was anticipated due to evidence that a prior art substance metabolized into the claimed compound upon ingestion by a patient. Recognition of the conversion process at the time of the prior art was not necessary to prove inherent anticipation. Id. at 1379-81. Thus, if SmithKline proved contributory infringement by showing that PHC anhydrate metabolizes into PHC hemihydrate upon ingestion, Smith-Kline may also have proved that PHC hemihydrate was inherent in the prior art. Nevertheless, because claim 1 is invalid for public use under § 102(b), SmithKline’s appeal concerning its contributory infringement claim is moot.
Similarly, SmithKline’s appeal of the district court’s ruling that injunctive relief [1321]*1321under 35 U.S.C. § 271(e)(4) is within the district court’s discretion is also moot. That ruling was not necessary for the district court’s judgment below and is immaterial to the determination of this appeal. This court, therefore, does not address that issue in this opinion.
III.
In summary, this court reverses the claim construction of the district court and holds that claim 1 covers any amount of crystalline paroxetine hydrochloride hem-ihydrate without further limitation. Based on the factual findings of the district court, this court affirms the district court’s finding that Apotex’s PHC anhydrate product will infringe claim 1 under that broad construction. Notwithstanding that conclusion, this court holds, based on the undisputed facts, that SmithKline’s clinical trials constituted a public use under § 102(b) rendering claim 1 invalid. Apotex is, therefore, not liable for infringing claim 1 of the '723 patent. This court affirms the district court’s judgment.
COSTS
Each party shall bear its own costs.
AFFIRMED.