Full opinion text
MEMORANDUM OF OPINION AND ORDER SCHWARZER, District Judge. TABLE OF CONTENTS Page I. Introduction 1382 II. Factual Background 1383 III. The Claims at Issue 1385 IV. Infringement 1380 A. General Principles 1386 B. The Product-by-Process Claims 1386 1. Claim Interpretation 1386 2. Infringement 1387 a. Tuddenham Human Factor VIII:C 1388 b. Plasma-derived Factor VIII:C 1388 Produced by Genentech c. Recombinant Factor VIII:C Produced by Genentech 1388 d. Doctrine of Equivalents 1388 e. Summary 1389 C. The Product Claims 1389 1. Claim Interpretation 1389 2. Infringement 1390 a. Plasma-derived Factor VIII:C Produced by Genentech 1390 b. Recombinant Factor VIII:C Produced by Genentech 1391 i. The Scope of the Product Claims 1391 (1) The Structure and Function of Recombinant Factor VIII:C 1391 (2) Genentech’s Statements 1392 (3) Genentech’s Response 1393 ii. Claims Limitations 1394 iii. Summary 1395 V. Inducement to Infringe 1395 VI. Non-Infringement Under 35 U.S.C. § 271(e)(1) 1395 VII. Inequitable Conduct ^39^ A. Background 1397 B. Materiality 1397 1. Insufficient Disclosure in the Abstract 1399 2. Cumulative Information 1399 VIII. Preliminary Injunction 1400 IX. Order 1401 I. Introduction This action alleges infringement of a patent covering a protein known as Factor VIII:C which plays an essential part in blood clotting. Hemophiliacs commonly suffer from an absence or deficiency of this protein and as a result are exposed to the risk of hemorrhaging from even a minor wound. The patent at issue claims highly concentrated and purified Factor VIII:C and a process for deriving it from human blood plasma. The principal issue raised is whether defendant Genentech, Inc.’s production of Factor VIII:C using recombinant technology infringes plaintiffs’ patent. Plaintiffs are Scripps Clinic and Research Foundation (Scripps), the owner of the relevant patents, and Revlon, Inc., the exclusive licensee. They filed this action against Genentech for infringement of United States Patent No. 4,361,509 (the ’509 patent) in November 1983. Gen-entech answered and cross-complained, alleging invalidity and unenforceability. The action was stayed pending Scripps’s application for a reissue patent. A companion action, Scripps Clinic and Research Foundation v. Chiron Corporation, No. C-83-5424-WWS, was also stayed pending decision of this case. Gen-entech and several other competing biotechnology firms contested Scripps’s reissue application before the Patent and Trademark Office (PTO). The PTO rejected several of Scripps’s new claims and required amendments of others, but finally issued Reissue Patent No. RE 32,011 (the ’011 patent) on October 22, 1985. The parties then resumed this litigation and conducted limited discovery. On August 1, 1986 the Court denied as premature Genentech’s motion for dismissal or summary judgment under 35 U.S.C. § 271(e)(1) and ordered Scripps to submit an offer of proof specifying each act alleged to be an infringement. Scripps filed its offer of proof on September 29, 1986. In October 1986, Scripps moved for a preliminary injunction and for summary judgment of infringement. In January 1987, Genentech filed motions to dismiss or for summary judgment of non-infringement and unen-forceability. On March 6, 1987 the Court conducted a hearing on the motions, following which the parties filed supplemental papers and responded to the Court’s request for additional information. The Court also received and has considered two declarations submitted in this action by Chiron Corporation. The following motions are presently before the Court for decision: (1) Scripps’s motion for partial summary judgment on the issue of Genentech’s infringement of the specified claims by Gen-entech’s manufacture, use and sale of Factor VIILC and Genentech’s inducement of Cutter to make Factor VIILC. (2) Scripps’s motion for a preliminary injunction enjoining Genentech from making, using or selling Factor VIILC and from inducing Cutter to infringe the patent claims. (3) Genentech’s motion under 35 U.S.C. § 271(e)(1) to dismiss or for summary judgment. (4) Genentech’s motion for summary judgment of unenforceability on the ground that the patent was obtained through inequitable conduct. (5) Scripps’s counter-motion for summary judgment that the patent is not unenforceable on inequitable conduct grounds. II. Factual Background The following facts are undisputed. Blood clotting, although not fully understood, may be generally described as follows. The clotting process begins when platelets in the bloodstream adhere to the site of a wound. The platelets would be dislodged, however, unless bound in place by strands of fibrin, an insoluble polymer. The formation of a network of fibrin from its soluble precursor, fibrinogen, is critical to clotting. That formation is the result of a complex series of interactions between blood proteins. Factor VIILC is one of the agents that activate other proteins essential to this process. A deficiency in Factor VIILC therefore prevents blood clotting. Two Scripps scientists, Drs. Zimmerman and Fulcher, developed a process for purifying and concentrating Factor VIILC from human and porcine blood plasma. On November 30, 1982 Scripps was issued the ’509 patent claiming both the process and the product of that process, “highly purified and concentrated VIILC.” Reissue patent 'Oil, issued October 22, 1985, added claims for human Factor VIILC preparations with specific characteristics relating to purity and concentration. Factor VIILC travels in the blood stream attached to a similar protein, Factor VIILRP, also known as von Willebrand Factor. Under the Scripps patent Factor VIILC is obtained by pouring large quantities of human or porcine blood plasma over monoclonal antibodies to Factor VIILRP which have been attached to a solid surface, such as small beads. Factor VIILRP, still attached to the Factor VIILC in the plasma, binds to these antibodies, while other particles in the plasma pass through the beads. This step of the process separates substantially pure VIILC/VIILRP complexes from the plasma. It is claimed to be a significant innovation over less successful techniques using either polyclonal antibodies or monoclonal antibodies to Factor VIILC. In the next step, the VIILC/VIILRP complexes are washed with a salt solution, which breaks the bonds between the Factor VIILC and Factor VIILRP and elutes the Factor VIILC, leaving the Factor VIILRP still bound to the antibodies. In the final step of the process, the Factor VIILC is filtered through another adsorption to concentrate and purify it further. Although the amino acid sequences of human and porcine plasma differ, Factor VIILC derived from either human or porcine plasma will clot human blood. Factor VIILC has also been isolated from bovine plasma but produces adverse side effects when administered to humans. Hence, the presently known plasma sources for Factor VIILC are limited. Because Factor VIILC exists in only minute quantities in blood, its recovery from plasma requires a large donor pool. As a result, concentrated Factor VIILC from human sources is expensive to produce. Moreover, there is evidence (though disputed) that Factor VIILC derived from human sources could carry impurities, including infectious agents, from the blood of donors. Defendant Genentech researches and develops biotechnology. In 1981 a team of Genentech scientists led by Dr. Vehar began research into producing human Factor VIILC through recombinant technology, which would obviate the need for a large pool of donors and eliminate the risk of transmitting infectious agents from donors. In the human body, Factor VIILC is produced by a gene in cells of the liver, kidneys, spleen and lymph glands and is then secreted into the bloodstream. The gene contains a stretch of DNA, which in turn is composed of a chain of nucleotides. Each nucleotide carries one of four bases (adenine, thymine, guanine and cytosine). The sequence of bases governs the production and sequence of amino acids composing a protein such as Factor VIILC. Thus, to produce Factor VIILC by recombinant technology, it was necessary first to identify the stretch of DNA responsible for Factor VIILC and then to clone it. Because Factor VIILC, now known to consist of a chain of 2,332 amino acids when in the bloodstream, is a much larger protein than any previously produced through recombinant technology, Genen-tech had to break new ground. It began by determining the sequence of amino acids in segments of human Factor VIILC from samples manufactured from blood plasma both by Dr. Tuddenham of Speywood Laboratories in England and by Genentech itself. Genentech then used the genetic information so acquired to translate the amino acid sequence of a short link of Factor VIILC into a complementary strand of DNA. This strand of DNA, called a probe, was inserted into a genomic library containing a complete set of human genes. The probe hybridized, or associated, with a portion of the gene for Factor VIILC. By repeating this process using the gene segment as a probe, Genentech was able to piece together the entire gene for Factor VIILC. The gene, found to consist of 186,-000 bases, was too large to transplant using the current technology. The coding information for Factor VIILC, however, is interspersed over less than one-twentieth of the gene. Messenger RNA (mRNA) carries only this essential coding information. Therefore, Genentech used a probe to locate mRNA in a human cell. The mRNA in turn probed a smaller genetic library constructed from a human cell found to be a site of Factor VIILC production; there the probe hybridized with DNA complementary to mRNA (cDNA). Finally, a complete strand of cDNA containing the essential coding information, inserted in a plasmid, was transplanted into a baby hamster kidney cell. There the gene dictated synthesis of Factor VIILC much as it would in a human cell. After the hamster cell manufactured the Factor VIILC, the protein was harvested and purified from the culture. Monoclonal antibodies to Factor VIILC were used in the purification process. Genentech first succeeded in manufacturing recombinant Factor VIILC by this process in April 1984. In December 1984 it entered into a research and development contract with Cutter under which Cutter would develop a method for commercial scale production of recombinant Factor VIILC and produce bioequivalency data required by the Food and Drug Administration (FDA). On April 18, 1986 Genentech filed European Patent Application number 85302734.0 claiming “human Factor VIH” and recombinant methods for its production. So far as the record shows, neither Genentech nor Cutter has as yet produced Factor VIILC in commercial quantities. III. The Claims at Issue Claims 13 and 14 common to the ’509 and ’Oil reissue patents and claims 17, 18, 24 through 29 and 34 of the ’Oil reissue patent are alleged to have been infringed by Genentech. Those claims are as follows: 13. Highly purified and concentrated human or porcine VIILC prepared in accordance with the method of claim 1. 14. Highly purified and concentrated human or porcine VIILC prepared in accordance with the method of claim 6. 17. A VIILC of claim 13, wherein said VIILC is human VIILC. 18. A VIILC of claim 14, wherein said VIILC is human VIILC. 24. A human VIILC preparation having a potency in the range of 134 to 1172 units per ml. and being substantially free of VIILRP. 25. A human VIILC preparation of claim 24, wherein the VIILC concentration is at least 160,000 fold purified relative to VIILC in plasma. 26. A human VIILC preparation of claim 24, wherein the ratio of VIILC to VIILRP is greater than 100,000 times the ratio in plasma. 27. A human VIILC preparation of claim 24, wherein said VIILC is isolated from VIILC/VIILRP and 90-100 percent of the VIILRP has been removed. 28. A human VIILC preparation having a specific activity greater than 2240 units/mg. 29. A human VIILC preparation of claim 28 wherein the potency is in the range of 134 to 1172 units/ml. 34. Highly purified and concentrated human or porcine VIILC prepared in accordance with the method of claim 30. Claims 1, 6 and 30, incorporated by reference above, state: 1. An improved method of preparing Factor VIII procoagulant activity protein comprising the steps of (a) adsorbing a VIILC/VIILRP complex from a plasma or commercial concentrate source onto particles bound to a monoclonal antibody specific to VIILRP, (b) eluting the VIILC, (c) adsorbing the VIILC obtained in step (b) in another adsorption to concentrate and further purify same, (d) eluting the adsorbed VIILC, and (e) recovering highly purified and concentrated VIILC. 6. The method according to claim 1, wherein aminohexyl agarose is employed in step (c) as the adsorbent. 30.An improved method of preparing Factor VIII procoagulant activity protein comprising the steps of (a) adsorbing a VIILC/VIILRP complex from a plasma or commercial concentrate source onto a substrate to which is bound a monoclonal antibody specific to VIILRP, (b) eluting the VIILC, (c) adsorbing the VIILC obtained in step (b) in another adsorption to concentrate and further purify same, (d) eluting the adsorbed VIILC, and (e) recovering highly purified and concentrated VIILC. Claims 13 and 14, the only asserted claims common to both the original ’509 patent and the ’Oil reissue patent, were amended in the ’Oil patent by addition of the words “human or porcine” before “VIILC”. The claims in litigation fall into two general categories: (1) product-by-process claims (claims 13, 14, 17, 18 and 34); and (2) product claims (claims 24 through 29). Because the legal analysis governing infringement differs in material respects, product-by-process claims and product claims will be discussed separately in Part IV of this opinion. The remainder of the opinion will address issues equally applicable to both categories. IV. Infringement A. General Principles Infringement occurs whenever a person “without authority makes, uses or sells any patented invention, within the United States during the term of the patent therefor ...” 35 U.S.C. § 271(a). “The patentee bears the burden of proving infringement by a preponderance of the evidence.” SRI Int’l v. Matsushita Elec. Corp. of Am., 775 F.2d 1107, 1123 (Fed.Cir.1985). A determination of infringement requires two steps: “first, the scope of the claims must be ascertained, and then the trier must decide whether the claims cover the accused device.” P.M. Palumbo v. Don-Joy Co., 762 F.2d 969, 974 (Fed.Cir.1985). “Infringement raises the legal issue of claim construction and the factual issue of whether the accused device infringes properly interpreted claims.” Martin v. Barber, 755 F.2d 1564, 1566 (Fed.Cir.1985). See also Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565, 1569 (Fed.Cir.1983); Matsushita, 775 F.2d at 1116 and 1118. A claim is construed in light of the claim language, the other claims, the prior art, the prosecution history, and the specification. Id., 775 F.2d at 1118. In addition, claims are normally interpreted as they would be by those of ordinary skill in the art. Palumbo, 762 F.2d at 975. A dispute over claim construction does not preclude summary judgment in the absence of material evidentiary disputes. Martin, 755 F.2d at 1567. Once the claims have been construed, they must be applied to the accused device to determine infringement. Matsushita, 775 F.2d at 1118. The court may find literal infringement if the accused device falls within the scope of the asserted claims as properly interpreted. Palumbo, 762 F.2d at 974. Infringement presents a question of fact, but, under Fed.R.Civ.P. 56, summary judgment is “appropriate, in a patent as in any other case, where there is no genuine issue of material fact and the movant is entitled to judgment as a matter of law.” Matsushita, 775 F.2d at 1116. See generally, Celotex Corp. v. Catrett, 477 U.S. 317, 106 S.Ct. 2548, 91 L.Ed.2d 265 (1986). The district court must view the evidence in the light most favorable to the nonmovant and draw all reasonable inferences in its favor. Matsushita, 775 F.2d at 1116; Martin v. Barber, 755 F.2d at 1566. The burden is on the nonmoving party, however, to identify a material evidentiary conflict in the record. “Mere denials or conclusory statements are insufficient.” Barmag Barmer Maschinenfabrik AG v. Murata Machinery, Ltd., 731 F.2d 831, 836 (Fed.Cir.1984); Matsushita, 775 F.2d at 1116. Moreover, “[t]he materiality of facts is viewed in light of the legal standard to be applied in the case.” Barmag, 731 F.2d at 836 (emphasis in original); see also Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). B. The Product-by-Process Claims 1. Claim Interpretation Claims 13, 14, 17, 18 and 34 are product-by-proeess claims. A product may be defined by the process of making it if the English language is inadequate to describe the invention. “However, the invention so defined is a product and not a process." In re Bridgeford, 357 F.2d 679, 682 (C.C.P.A.1966) (emphasis added). The question whether a product-by-process claim is infringed is not to be confused with the question whether it is patentable. An original process to manufacture a product already in the prior art may not be used to patent that product by means of a product-by-process claim. Although the new process may be patentable under a process claim, the product itself is not patentable because it is unoriginal. In that case the product-by-process claim is not patentable because it claims the product and not the process. See In re Thorpe, 777 F.2d 695, 697 (Fed.Cir.1985) (“The patentability of a product does not depend on its method of production”). It does not follow, however, that once a product-by-process patent issues, it is infringed by any product that would infringe a product claim, as Scripps argues. A"' product-by-process claim is infringed only by a product produced by following the same process described in the claim. The Supreme Court held a product-by-process claim uninfringed in Cochrane v. Badische Anilin & Soda Fabrik, 111 U.S. 293, 4 S.Ct. 455, 28 L.Ed. 433 (1884) because the defendants had not been shown to follow the process describing the product. The plaintiff argued that the accused product was “physically, chemically, and in [functional] properties similar” to the patented product. Id. at 310, 4 S.Ct. at 464. According to the Court, however, the patent defined the product only as the product of the described process. “Therefore, unless it is shown that the process of [the patent] was followed to produce the defendants’ article, or unless it is shown that that article could not be produced by any other process, the defendants’ article cannot be identified as the product of the process of [the patent].” Id. Two Courts of Appeals have reached the same conclusion. The Third Circuit has held that “[a] patent granted on a product claim describing one process grants no monopoly as to identical products manufactured by a different process.” Paeco, Inc. v. Applied Moldings, Inc., 562 F.2d 870, 876 (3d Cir.1977). Similarly, the Seventh Circuit has stated that “a claim [patenting a] product [may] define it as the product resulting from a described process and, if the character of the product depends upon the manner in which it has been produced, ordinarily, it should be claimed only as the thing produced by the specific process.” National Carbon Co. v. Western Shade Cloth Co., 93 F.2d 94, 96 (7th Cir.1937), cert. denied, 304 U.S. 570, 58 S.Ct. 1039, 82 L.Ed. 1535 (1938). See also 2 D. Chisum, PATENTS § 8.05, 8-67 (1986) (“Most decisions hold that [a product-by-process] claim is infringed only by a product made through a substantially identical process Scripps contends that two Court of Customs and Patent Appeals cases “indicate” that court’s disagreement with federal cases construing product-by-process claims as limited to products produced by the disclosed process. Both cases cited, In re Bridgeford, 357 F.2d 679 (C.C.P.A.1966) and In re Hirao, 535 F.2d 67 (C.C.P.A.1976), involved appeals from the denial of patent claims by the PTO Board of Appeals. Neither expressed disapproval of construing product-by-process claims, in the context of infringement suits, as describing only a product made by the specified process. The court acknowledged in In re Bridgeford that, while a product-by-process claim describes a product, [t]he policy of the Patent Office in permitting product-by-process type claims to define a patentable product, where necessary, has developed with full cognizance of. the fact that in infringement suits some courts have construed such claims as covering only a product made by the particular process set forth in the claim and not to the product per se. 357 F.2d at 682 n. 5 (emphasis in original). Similarly, in a footnote in In re Hirao, the court remarked on the distinction between the standard for patentability of a pure process claim and the standard for infringement of a product-by-process claim. 535 F.2d at 69 n. 3. Neither of these decisions, nor any others of which the Court is aware, support Scripps’s contention. Accordingly, to prove infringement of the product-by-process claims, Scripps must show by a preponderance of the evidence that the accused product was the result of following the processes described in the claims or that the accused product could not have been the result of any other process. See Cochrane, 111 U.S. at 310, 4 S.Ct. at 464. 2. Infringement a. Tuddenham Human Factor VIII.'C Scripps contends that Genentech infringed by using human plasma-derived Factor VIII:C produced by Dr. Tuddenham of Speywood Laboratories in England. Genentech used the Tuddenham Factor VIII:C to determine the protein content, amino acid sequence, structure and functional properties of human Factor VIII:C. The record reveals, however, that Genen-tech’s entire supply of Tuddenham Factor VIILC was received and used between 1982 and 1984, prior to reissue of Scripps’s ’Oil patent in October 1985. Because product-by-process claims 13 and 14 were the sole asserted claims in force prior to 1985, the Tuddenham Factor VIILC literally infringed Scripps’s patent only if it was prepared using the processes described in those claims. The record contains uncontroverted evidence that the Tuddenham Factor VIILC was made using the identical process described in claim 1 and incorporated by reference in claim 13. Dr. Tuddenham first purified a commercial concentrate through monoclonal antibodies to Factor VIILRP. The Factor VIILC was eluted, adsorbed in an adsorption of monoelonals to Factor VIILC, and then eluted again. Vehar depo., at 78-79. The end product was highly purified and concentrated human Factor VIILC, as defined in the claims, with specific activities greater than 2240 u/mg and potencies in the range of 134-1172 u/ml. Offer of Proof (O.P.) at 12-13 and Ex. 3. Genentech’s use of the Tuddenham Factor VIILC thus infringed claim 13. 35 U.S.C. § 271(a). Scripps concedes that Dr. Tuddenham did not make use of a second adsorption of aminohexyl agarose as described in claim 6 and incorporated in claim 14. Hence, the Tuddenham Factor VIILC did not infringe claim 14. b. Plasma-derived Factor VIILC Produced by Genentech Scripps concedes that the Factor VIILC produced by Genentech from human plasma was obtained using monoclonal antibodies to Factor VIILC, not Factor VIILRP. There is no evidence, therefore, that plasma-derived Factor VIILC manufactured by Genentech infringed the product-by-process claims. c. Recombinant Factor VIILC Produced by Genentech In producing Factor VIILC using recombinant processes, Genentech obviously used processes other than those disclosed in the product-by-process claims. d.Doctrine of Equivalents Scripps contends that even if the Tuddenham Factor VIILC and the plasma-derived and recombinant Factor VIILC manufactured by Genentech did not literally infringe all the product-by-process claims, they nonetheless infringed the claims under the doctrine of equivalents. The doctrine of equivalents was “designed to protect a patentee from an in-fringer who appropriates the invention but avoids the literal language of the claims.” Atlas Powder Co. v. E.I. du Pont De Nemours & Co, 750 F.2d 1569, 1579 (Fed.Cir.1984). The doctrine recognizes that although an accused product does not literally infringe a patented product, it may in fact be “substantially the same thing, used in substantially the same way, to achieve substantially the same result,” and so infringe. Matsushita, 775 F.2d at 1123. The doctrine was “judicially devised to do equity,” Hughes Aircraft Co. v. United States, 717 F.2d 1351, 1361 (Fed.Cir.1983), and applies only if literal infringement is not found, Loctite Corp. v. Ultraseal, 781 F.2d 861, 870 (Fed.Cir.1985). Scripps has successfully proved that the Tuddenham Factor VIILC literally infringed claim 13 of the patent. Furthermore, as discussed in succeeding sections, the Factor VIILC manufactured by Genentech both from plasma and recombinantly literally infringed product claims in the patent. See infra at 1390-1395. Genentech has thus not avoided the literal language of the patent while appropriating the invention; rather, it has directly infringed claims of the patent. Therefore, Scripps is not entitled to the equitable application of the doctrine of equivalents. In any event, Scripps’s contention that the accused Factor VIILC infringed the product-by-process claims under the doctrine of equivalents, even though it was not produced according to every step in those claims, is merely an attempt to evade the limitation inherent in claiming the product of a process. Application of the doctrine of equivalents in this context would render meaningless the necessity of establishing infringement of a product-by-process claim by demonstrating that “the process of [the patent] was followed to produce the defendants’ article, or ... that the article could not be produced by any other process.” Cochrane, 111 U.S. at 310, 4 S.Ct. at 464. Scripps is therefore not entitled to application of the doctrine of equivalents in this context as a matter of law. e. Summary The undisputed facts establish Genen-tech’s infringement of claim 13 by its use of the Tuddenham Factor VHI:C, and Scripps’s motion must be granted on that claim. In all other respects, Scripps’s motion based on infringement of the product-by-process claims is denied. C. The Product Claims 1. Claim Interpretation Scripps also alleges infringement of product claims 24 through 29 covering concentrated preparations of “human Factor VIILC.” According to Scripps, these claims cover preparations, in the specified ranges of purity and potency, of Factor VIILC with the functional and structural characteristics of the protein as it occurs naturally in humans. Genentech, on the other hand, argues that Scripps’s claims are limited to Factor VIILC derived from human blood plasma. The issue posed is whether the asserted product claims must be interpreted to apply solely to concentrates of Factor VIILC derived directly from human blood plasma or whether they extend also to other concentrates of Factor VIILC having the same characteristics as those derived from human blood plasma. “A claim is construed in light of the claim language, the other claims, ... and the specification.” Matsushita, 775 at 1118. Claims 24 through 29 each claim a “human VIILC preparation,” but do not specify whether the VIILC must be derived directly from the bloodstream. In contrast, the patent’s process and product-by-process claims all incorporate the limitation that the Factor VIILC is filtered “from a plasma or commercial concentrate source.” Genentech would have the Court read this limitation into claims 24 through 29 as well. The law, however, is clear that “when a patent claim does not contain a certain limitation and another claim does, that limitation cannot be read into the former claim in determining ... infringement.” Matsushita, 775 F.2d at 1122. Claims 24 through 29 cannot be read as limited to Factor VIILC recovered directly from human plasma. Rather, they claim preparations of the disclosed purity or concentration having characteristics specific to Factor VIILC found in humans. Genentech also points out that the preferred embodiment described in the specification discloses a process for filtering Factor VIILC from human or porcine plasma and urges the Court to read this limitation into the claims. This argument is “legally unsound.” Environmental Designs v. Union Oil Co. of Cal., 713 F.2d 693, 699 (Fed.Cir.1983), cert. denied, 464 U.S. 1043, 104 S.Ct. 709, 79 L.Ed.2d 173 (1984). “The specification must be sufficiently explicit and complete to enable one skilled in the art to practice the invention, while a claim defines only that which the patentee regards as his invention ... The claim, not the specification, measures the invention ...” Id. The law does not require that an applicant describe in his specification every conceivable and possible future embodiment of his invention. The law recognizes that patent specifications are written for those skilled in the art, and requires only that the inventor describe the “best mode” known at the time to him of making and using the invention. Matsushita, 775 F.2d at 1121 (emphasis in original). Scripps is entitled to claim purified Factor VIILC having the characteristics of human Factor VIILC, whether derived through its disclosed process or any other process achieving the same result. Interpretation of claim language is also aided by reference to the prosecution history and prior art. Matsushita, 775 F.2d at 1118. During the prosecution of its reissue patent, Scripps distinguished the prior art contained in an article by Dr. Vehar on the ground that Dr. Vehar’s work involved only bovine plasma, “whereas all of [Scripps’s) claims, except 13, 14 and 40 [three claims that did not specify the source of the Factor VIILC], are literally specific to human VIILC.” Scripps enumerated the following differences between bovine and human Factor VIILC: The difference in species is particularly important both from a scientific and therapeutic point of view. Vehar reports a triplet in gel electrophoresis, which differs from the gel pattern reported by applicants. The molecular weights reported for bovine VIILC are also quite different from those of human VIILC.... The bovine VIILRP/VIILC complex is quite different from the human VIILRP/VIILC complex. The bovine complex is very difficult to disassociate ... Lavergne ... summarized some of the differences between various species VIII including bovine and human. These reported differences include: carbohydrate content: Human 6%, Bovine 20%; bovine induces direct aggregation of human platelets without ristocetin. Specific antisera raised against purified human and non-human Factor VIII show a poor degree of cross-reactivity which is indicative of distinct antigenic structure. Humans treated with bovine VIILC develop antibodies to it_ [T]here is a difference of a factor of 20 times between bovine and human antibody inhibition of human Factor VIII and a difference in respective thrombin activity ... The species difference and the resulting differences in amino acid sequences, antigenicity and efficacy in therapeutic use show they are different. Reissue File History at 00216-18. The examiner was persuaded “that animal VIILC is not the equivalent of Human VIILC ...” Id. at 00231. The prosecution history thus makes clear that both Scripps and the examiner considered the term “human VIILC” to be descriptive not of its derivation from human plasma but of its fundamental characteristics peculiar to the species. Such characteristics as amino acid sequence, antigenicity, and efficacy in therapeutic use distinguish the Factor VIILC of different species. The excerpts quoted by Genentech from deposition testimony of Drs. Katz-mann and Zimmerman, Scripps’s experts, that “human” means “obtained from human blood,” are not probative on the issue of interpreting the claims. Dr. Katzmann’s answer related to Factor V, not Factor VIII, and Dr. Zimmerman’s answer did not purport to give an interpretation of the particular claim language. Human Factor VIILC as claimed in the patent therefore applies to any Factor VIILC preparation, regardless of how produced, having the same material structural and functional characteristics as the plasma-derived preparation. 2. Infringement a. Plasma-derived Factor VIILC Produced by Genentech Genentech does not dispute that after October 22, 1985, when the 'Oil patent issued, it sold to Cutter purified Factor VIILC produced by it from human plasma and having characteristics relating to potency and purity claimed in Scripps’s product claims. Claim 24 claims a “human VIILC preparation having a potency in the range of 134 to 1172 units per ml. and being substantially free of VIILRP.” The record contains uncontradicted evidence that Genentech produced preparations of human Factor VIILC from human plasma with potencies in the range of 134 to 1172 units/ml. which were substantially pure of Factor VIILRP. O.P. at 15, Exs. 12 and 14, Scripps’s letter of May 19, 1987. These preparations read on each element of claim 24 and hence infringed that claim. Claim 24 is incorporated by reference in claims 25, 26 and 27. Claim 25 further requires that the preparation be “at least 160,000 fold purified relative to VIILC in plasma.” There is undisputed evidence that Genentech produced Factor VIILC preparations with fold purifications and po-tencies in the claimed ranges, and hence infringed claim 25. Id. Claims 26 and 27, in addition to incorporating claim 24, also require, respectively, that the ratio of Factor VIILC to Factor VIILRP be greater than 100,000 times the ratio in plasma and that 90-100 percent of the Factor VIILRP be removed. Scripps has offered no evidence on these elements of claims 26 and 27 and therefore is not entitled to judgment on these claims. Claim 28 claims a “human VIILC preparation having a specific activity greater than 2240 units/mg.” The undisputed evidence establishes that Genentech’s Factor VIILC preparations met this requirement as well, id., and therefore infringed claim 28. Finally, claim 29 claims a preparation of Factor VIILC of claim 28 with a potency in the range of 134 to 1172 units per ml. This claim was also infringed by Genentech’s plasma-derived Factor VIILC. The undisputed facts therefore establish that Genentech’s plasma-derived Factor VIILC infringed claims 24, 25, 28 and 29. b. Recombinant Factor VIILC Produced by Genentech The Court has interpreted the claim language “human VIILC” as not limited to Factor VIILC produced from human blood plasma. Supra at 1389-1390. The remaining issue is whether Factor VIILC produced by recombinant processes infringes the product claims so interpreted. To resolve that issue two subsidiary questions must be answered: i. Does recombinant Factor VIILC fall within the scope of the product claims? ii. If so, does it conform to the claims limitations? i. The Scope of the Product Claims (1) The Structure and Functions of Recombinant Factor VIILC. In Graver Tank & Mfg. Co., Inc. v. Linde Air Products Co., 339 U.S. 605, 607, 70 S.Ct. 854, 855-56, 94 L.Ed. 1097 (1950), the Supreme Court set forth the test for infringement: [I]n determining whether an accused device or composition infringes a valid patent, resort must be had in the first instance to the words of the claim. If accused matter falls clearly within the claim, infringement is made out and that is the end of it. The undisputed physical evidence, confirmed by Genentech’s own consistent statements, establishes that Factor VIILC produced by recombinant processes falls clearly within the product claims as here interpreted. The production of Genentech’s recombinant Factor VIILC, although it takes place in hamster rather than human cells, is directed by the controlling human gene. See supra at 1384-1385. That gene, transplanted from a human cell to a hamster cell, determines the amino acid sequence and other fundamental structural traits and functions of the protein. Genentech researchers have described the process in the following technical terms: “cloned full-length factor VIII protein coding sequences assembled into a plasmid direct the synthesis of biologically active factor VIII when transfected into cultured mammalian cells.” Wood, Capon, Simonsen, Eaton, Gitschier, Keyt, Seeburg, Smith, Hollingshead, Wion, Delwart, Tuddenham, Vehar & Lawn, Expression of active human factor VIII from recombinant DNA clones, Nature, November 22, 1984, 1984 reprint, at 1 [hereinafter Vehar & Lawn]. In effect, Genentech’s process transfers the site of Factor VIII:C production (1) from the human body to the laboratory and (2) from the cells of the human kidneys, liver, spleen and lymph glands to the cells of hamster kidneys. The master plan for Factor VIII:C production, however, remains constant. Human genetic material, extracted from human cells, is responsible for the production of recombinant Factor VIII:C. The same genetic material dictates the structure and function of the protein regardless of the site of the protein’s production. That genetic material directs the identical amino acid sequence whether it remains in a human cell or is transplanted to a hamster cell. The testimony of Dr. Zimmerman cited by Genentech, that human VIII:C is “VIII:C purified from humans and containing amino acid sequence unique to humans,” is entirely consistent with the conclusion that recombinant Factor VIII:C is “human.” (2) Genentech’s Statements In an article published in Nature, Genen-tech researchers concluded: “We have demonstrated by several criteria that the DNA sequences isolated here encode human factor VIII ... [T]he amino acid sequence derived from factor VIII preparations and the primary structure of the protein predicted by the cloned sequence are essentially identical.” Vehar & Lawn, supra, at 6 (emphasis added). In an article published in Scientific American in March 1986, after commencement of this action, Genentech’s Drs. Lawn and Vehar stated: “Bioengineered factor VIII does clot hemophilic blood. Indeed, it has been found to be equivalent in every way to the blood-derived protein.” Lawn & Vehar, The Molecular Genetics of Hemophilia, Sci.Am., March 1986, at 52 (emphasis added). In their presentation to the Fifth International Symposium on Hemophilia Treatment in September 1986, Drs. Lawn and Vehar stated: “The bioengineered factor VIII is virtually indistinguishable from the plasma derived factor in both in vitro and in vivo experiments ...” Address by Lawn, Eaton, Gitschier, Tuddenham, Ve-har, Wion and Wood before the Fifth International Symposium on Hemophilia Treatment (Sept.1986) (emphasis added). Genentech’s European Patent Application takes the same position. It describes Genentech’s recombinant process as follows: Thus, the present invention is based upon the successful use of recombinant DNA technology to produce functional human factor VIII, and in amounts sufficient to prove identification and functionality and to initiate and conduct animal and clinical testing as prerequisites to market approval. The product, human factor VIII, is suitable for use, in all of its functional forms, in the prophylactic or therapeutic treatment of human beings diagnosed to be deficient in factor VIII coagulant activity. Accordingly, the present invention, in one important aspect, is directed to methods of diagnosing and treating classic hemophilia (or hemophilia A) in human subjects using factor VIII and to suitable pharmaceutical compositions therefor. The present invention further comprises essentially pure, functional human factor VIII. The product produced herein by genetically engineered appropriate host systems provides human factor VIII in therapeutically useful quantities and purities. In addition, the factor VIII hereof is free of the contaminants with which it is ordinarily associated in its non-recombinant cellular environment. European Patent Application at 7 (emphasis added). The term “human factor VIII” is defined in the application as denoting] a functional protein capable, in vivo or in vitro, of correcting human factor VIII deficiencies ... Such factor VIII is produced by recombinant cell culture systems in active form(s) corresponding to factor VIII activity native to human plasma ... The factor VIII protein produced herein is defined by means of determined DNA gene and amino acid sequencing, by physical characteristics and by biological activity. Id. at 15-16. The term “functional human factor VIII” is further defined in the application as follows: Thus, human factor VIII in functional form, i.e., “functional human factor VIII”, is capable of catalyzing the conversion of factor X to Xa in the presence of factor IXa, calcium, and phospholipid, as well as correcting the coagulation defect in plasma derived from hemophilia A affected individuals, and is further classified as “functional human factor VIII” based on immunological properties demonstrating identity or substantial identity with human plasma factor VIII. Id. at 17 (emphasis added). The application lists the functions of recombinant Factor VIILC as follows: a) Correction of factor VIII deficient plasma. b) Activation of factor X to factor Xa in the presence of factor IXa, calcium and phospholipid. c) Inactivation of the activity observed in a) and b) by antibodies specific for factor VIII. d) Binding of the activity to an immobilized monoclonal antibody column specific for factor VIII. e) Activation of the factor VIII activity by thrombin. f) Binding of the activity to and subsequent elution from immobilized von Willenbrand factor. Id. at 7. Declarations submitted by experts in the field confirm that the comparison tests performed by Genentech demonstrate identity of recombinant Factor VIILC with the plasma-derived preparation. See Declarations of Drs. Zimmerman and Fulcher; Dr. Hoyer; and Dr. Sadler. (3) Genentech’s Response In response, Genentech has offered three categories of evidence to demonstrate that recombinant Factor VIILC does not fall within the scope of these product claims. The question is whether that evidence raises a genuine issue of material fact, precluding summary judgment for Scripps on these claims. First, Genentech asserts that all recombinant Factor VIILC molecules, because they are derived from identical genes, are likely to have identical amino acid sequences. Individual molecules of Factor VIILC in a preparation derived from the plasma of many donors may differ from the species norm in that they may contain slight variations in amino acid sequence. This phenomenon is known as polymorphism. There is no evidence, however, that this difference is material. Dr. Sadler, the witness on whose testimony Genentech’s argument is based, testified that “[b]y definition a polymorphism is a variation in sequence that is not known to influence function ... A polymorphism that influences function is called a mutation, a disease." Sadler Depo. at 26. Dr. Vehar stated in his declaration that “recombinant Factor VIILC may differ in composition from human Factor VIILC yet remain functional.” Vehar Decl. at 2. Indeed, Genentech claims to be experimenting with recombinant Factor VIILC manufactured from an abbreviated gene and containing only 1566 amino acids. Presumably, such a protein would be functionally equivalent to Factor VIILC, but, in any event, it is as yet no more than a speculative possibility and hence immaterial. What the evidence clearly shows is that complete identity of amino acid sequence is not essential to the material structure and functions of human Factor VIILC. The contention therefore raises no triable issue with respect to infringement. Second, Genentech contends that preparations of recombinant Factor VIILC differ materially from preparations of plasma-derived Factor VIILC in that the latter may contain human viruses, while the former are bound to be free of human infectious agents. See European Patent Application at 17. It may be that in this respect Gen-entech’s product is superior to Scripps’s. It does not follow, however, that because Genentech’s process may be capable of producing superior human Factor VIILC preparations, those improved preparations fall outside the claims. The term “human VIII:C” is not a claim limitation excluding Factor VIII:C preparations free of human infectious agents, since such impurities are obviously extrinsic to the claims. See Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 868 (Fed.Cir.1985). This contention therefore raises no triable issue of fact. Genentech’s final contention is that Scripps has failed to sustain its burden because it has not established that “the glycosylated carbohydrate is the same for human VIII:C and recombinant VIIIrC.” Opposition to Motion for Summary Judgment at 19. The only evidence offered by Genentech on this point consists of the following statement in Dr. Vehar’s declaration: Since the type of glycosylation' is specified by the nature of the cell, the carbohydrate structure of factor VIIIrC produced by non human cells is expected to be different from that of human cells. The carbohydrate composition and pattern of glycosolation may vary between human VIIIrC and recombinant VIIIrC. There is no evidence that carbohydrates associated with human VIIIrC are the same as those associated with recombinant VIIIrC. The glycosolated carbohydrates associated with recombinant VIIIrC are likely to be different from the glycosolated carbohydrates associated with human VIIIrC. Vehar Deck at 118. A similar assertion is found in Genentech’s European Patent Application, which states that “the location of and degree of glycosylation may depend on the nature of the host cellular environment.” European Patent Application at 16. It appears to be undisputed that the carbohydrate structure of Factor VIIIrC may be affected by the host cell; in that respect Factor VIIIrC may differ depending on whether it is derived from human plasma or produced in hamster cells. Moreover, it is also clear that the carbohydrate content of certain animal Factor VIIIrC (as distinguished from human Factor VIIIrC produced in animal host cells), is significantly different from that of human Factor VIIIrC. For example, Scripps asserted before the PTO that the carbohydrate content of the bovine Faetor VIIIrC produced by Dr. Vehar differed materially from that of human Factor VIIIrC. Reissue File History at 00216-18. There is no evidence, however, that any difference in the carbohydrate content of plasma-derived and recombinant human Factor VIIIrC affects the relevant structure or functions of the material. Dr. Ve-har, in an article published contemporaneously with his instant declaration, refers to the authors' observation “suggesting] that the presence of the highly glycosylated B domain [of Factor VIIIrC] has little effect on factor VIII coagulant activity.” Eaton, Wood, Eaton, Hass, Hollingshead, Wion, Mather, Lawn, Vehar & Gorman, Construction and Characterization of an Active Factor VIII Variant Lacking the Central One-Third of the Molecule, Biochemistry, December 30, 1986, at 8346. His declaration contains no evidence that differences in carbohydrate content affect the functioning of human Factor VIIIrC, and, as previously demonstrated, Genen-tech’s consistent position has been that plasma-derived and recombinant Factor VIIIrC are identical in all material respects. See supra at 1392-1393. To conclude, Scripps has shown that recombinant Factor VIIIrC is structurally and functionally the same as plasma-derived Factor VIIIrC. On the motion for summary judgment, Genentech has the burden of coming forward with evidence raising a material issue of fact. See Proler Steel Corp. v. Luria Bros. & Co., 417 F.2d 272, 274 (9th Cir.1969). That evidence, to be material, would have to permit a trier of fact to find that recombinant Factor VIIIrC does not qualify as “human VIIIrC” within the meaning of the claims. No such facts having been offered, the Court holds as a matter of law that recombinant Factor VIIIrC falls within the scope of the asserted product claims. See Martin v. Barber, 755 F.2d 1564, 1567 (Fed.Cir.1985). ii. Claims Limitations Scripps has produced uncontroverted evidence that Genentech’s recombinant Factor VIILC had potencies in the range of 134 to 1172 u/ml, fold purifications of at least 160,000, and specific activities greater than 2240 units/mg. See O.P., Exs. 12-14 and Scripps’s letter of May 19, 1987. These preparations read on each element of claims 24, 25, 28 and 29. Genentech’s recombinant Factor VIILC therefore infringed these claims. iii. Summary The undisputed facts establish Genen-tech’s infringement of claims 24, 25, 28 and 29 by its production of plasma-derived and recombinant Factor VIILC, and Scripps’s motion must be granted on those claims. In all other respects its motion based on infringement of the product claims is denied. V. Inducement to Infringe Seripps alleges that Genentech violated 35 U.S.C. § 271(b) by inducing Cutter to infringe the patent through the manufacture of both human and recombinant Factor VIILC. 35 U.S.C. § 271(b) provides that “[wjhoever actively induces infringement of a patent shall be liable as an infringer.” “This subsection contemplates that the inducer shall have been an active participant in the line of conduct of which the actual infringer was guilty.” Sims v. Western Steel Co., 551 F.2d 811, 817 (10th Cir.), cert. denied, 434 U.S. 858, 98 S.Ct. 182, 54 L.Ed.2d 131 (1977). To prove violation of § 271(b), Seripps must therefore demonstrate direct infringement by Cutter and that Genentech acted with the intent to induce such infringement. See id.; Moleculon Research Corp. v. CBS, Inc., 793 F.2d 1261, 1272 (Fed.Cir.1986), cert. denied, — U.S. -, 107 S.Ct. 875, 93 L.Ed.2d 829 (1987). There is no question that Genentech delivered to Cutter materials found to have infringed, including recombinant and plasma-derived human Factor VIILC, with the intent that Cutter itself would “use its reasonable best efforts to develop [recombinant Factor VIILC] at its facilities, including ... development of a commercial scale process for the production of [recombinant Factor VIILC].” Research and Development Agreement Between Genentech and Cutter Regarding Factor VIII. O.P., Ex. 19 at 13, ¶ 2.2. There is also no doubt that Genentech intended Cutter to use plasma-derived Factor VIILC manufactured by both Genentech and Cutter which has been found to infringe. See supra at 1390-1391. Accordingly, Genentech is found to have induced Cutter to infringe the ’011 patent in violation of 35 U.S.C. § 271(b). VI. Non-Infringement Under 35 U.S.C. § 271(e)(1) Genentech has renewed its motion for dismissal or summary judgment of non-infringement under 35 U.S.C. § 271(e)(1), which the Court denied without prejudice as premature by order of August 1, 1986. The Court has reconsidered its prior order in light of the memoranda submitted and the arguments made in connection with these motions, and for the reasons stated denies the motion. Section 271(e)(1) provides: It shall not be an act of infringement to make, use, or sell a patented invention (other than a new animal drug or veterinary biological product (as those terms are used in the Federal Food, Drug, and Cosmetic Act and the Act of March 4, 1913)) solely for uses reasonably related to the development and submission of information under a Federal law which regulates the manufacture, use, or sale of drugs. This provision, enacted under the Drug Price Competition and Patent Term Restoration Act of 1984 (“Act”), Pub.L. 98-417, 98 Stat. 1585, overruled the Federal Circuit’s 1984 decision in Roche Products, Inc. v. Bolar Pharmaceutical Co., Inc., 733 F.2d 858 (Fed.Cir.), cert. denied, 469 U.S. 856, 105 S.Ct. 183, 83 L.Ed.2d 117 (1984). The defendant in Roche had obtained from a foreign manufacturer a generic drug covered by a domestic patent in order to conduct bioequivaleney tests necessary for FDA approval. The Federal Circuit held this use infringing, notwithstanding that it was “limited” to “testing and investigation strictly related to FDA drug approval.” Id. at 861. The 1984 Act established a streamlined procedure for FDA approval of generic drugs to hasten their introduction into the marketplace. Section 271(e)(1), enacted as § 202 of the 1984 Act, responded to congressional concern that under Roche the arrival of generics on the market would be delayed because bioequivalency testing required by the FDA could not begin until after expiration of the patent. See H.R.Rep. No. 98-857, 98th Cong., 2d Sess., reprinted in 1984 U.S.Code Cong. & Ad. News 2647, 2678-79, 2692-93. Genentech argues that all its uses of Factor VIIT.C, though not solely for purposes related to FDA testing, bear some reasonable relationship to such purposes and hence are noninfringing under § 271(e)(1). The construction of § 271(e)(1) that Genentech urges the Court to adopt would, in effect, eliminate the express statutory limitation “solely for” and thereby immunize any use of a patented invention so long as some aspect of that use is reasonably related to FDA testing. This broad construction defies the plain mandate of the statute and the intent of Congress. The statute’s meaning is clear: the use of a patented invention is protected so long as that use is solely for purposes reasonably related to meeting the reporting requirements of federal drug laws. Therefore, to establish entitlement to the statutory exemption, Genentech must demonstrate that it made and used plasma-derived and recombinant Factor VIII:C preparations solely for the purpose of meeting FDA reporting requirements. This interpretation accords with the intent of Congress in enacting § 271(e)(1). The comments of the authors of the House Report emphasize the narrowness of the exemption. For example, the Report states that “a generic drug manufacturer may obtain a supply of a patented drug product during the life of the patent and conduct tests using that product if the purpose of those tests is to submit an application to FDA for approval.” Id. at 2689. It further states that the only activity which will be permitted by the bill is a limited amount of testing so that generic manufacturers can establish the bioequivalency of a generic substitute. The patent holder retains the right to exclude others from the major commercial marketplace during the life of the patent. Thus, the nature of the interference with the rights of the patent holder is not substantial. Id. at 2692. Even if the uses to which Genentech and Cutter put the Factor VIII:C were reasonably related to meeting FDA requirements, they certainly were not solely related to that purpose. Those uses also related, among other things, to preparation of Gen-entech’s application for a European patent and to performance of the Genentech-Cut-ter agreement to develop a process for manufacturing Factor VIII:C on a commercial scale. Pursuant to that agreement, Genentech supplied Cutter with Factor VIII:C and received substantial sums from and agreed to share proprietary rights with Cutter. Furthermore, the agreement contemplates the marketing of recombinant Factor VIII:C outside the United States before expiration of the Scripps patent. These sales and uses of Factor VIII:C, serving multiple purposes unrelated to meeting FDA requirements, clearly lie beyond the protection of § 271(e)(1). Genentech’s motion to dismiss or for summary judgment under 35 U.S.C. § 271(e)(1) is therefore denied. VII. Inequitable Conduct Genentech has moved for summary judgment on the ground that the ’Oil patent was obtained by inequitable conduct and is therefore unenforceable. Scripps has made a counter-motion for summary judgment on this issue. 35 U.S.C. § 282(1) provides that unen-forceability of a patent is a defense to infringement. See generally J.P. Stevens & Co., Inc. v. Lex Tex. Ltd., 747 F.2d 1553, 1560-62 (Fed.Cir), cert. denied, 474 U.S. 822, 106 S.Ct. 73, 88 L.Ed.2d 60 (1984). A patent applicant owes the PTO an “uncompromising duty” of candor. Precision Instrument Mfg. Co. v. Automotive Maintenance Machinery Co., 324 U.S. 806, 816, 65 S.Ct. 993, 998, 89 L.Ed. 1381, reh’g denied, 325 U.S. 893 (1945). The intentional failure to disclose material prior art constitutes inequitable conduct. In re Jerabek, 789 F.2d 886, 889 (Fed.Cir.1986). If the court determines that inequitable conduct occurred, all the patent’s claims — “not just the particular claims to which the inequitable conduct is directly connected — are unenforceable.” J.P. Stevens, 747 F.2d at 1561. The party alleging inequitable conduct must prove by clear and convincing evidence “a threshold of materiality of the nondisclosed information and of the prosecutor’s intent.” In re Jebarek, 789 F.2d at 889. See also J.P. Stevens, 747 F.2d at 1559. Once threshold materiality and intent have been established, the court “must conduct a balancing test to determine, as a matter of law, whether the scales tilt to a conclusion that ‘inequitable conduct’ occurred.” In re Jerabek, 789 F.2d at 890; J.P. Stevens, 747 F.2d at 1560. The balancing of equitable considerations to determine unenforceability is a matter of law in the province of the court. American Hoist & Derrick Co. v. Sowa & Sons, Inc., 725 F.2d 1350, 1364 (Fed.Cir), cert. denied, 469 U.S. 821, 105 S.Ct. 95, 83 L.Ed.2d 41 (1984). A. Background The ’Oil patent application included five claims for monoclonal antibodies — claims 24 through 29. Claims 25 through 29 depended on claim 24 which, as amended, claimed antibodies with the following properties: A monoclonal antibody for isolation of VIILC from VIILC/VIILRP, said monoclonal being specific to VIILRP and remaining complexed to VIILRP when subjected to a saline solution elution and when said antibody is bound to a substrate. Genentech contends that Scripps, in prosecuting its reissue application, failed to disclose to the PTO a reference to an abstract by Drs. Meyer, Obert, Zimmerman and Édgington entitled Monoclonal Antibodies Specific for Factor VIII from Cellular Hybrids, No. 395 (the Meyer abstract), which Genentech claims constitutes material prior art. Although the Meyer abstract was not directly disclosed to the examiner, it was cited in two articles by Dr. Muller (reference AAA) and by Drs. Meyer and Edgington (reference RS) submitted to the PTO. The examiner directed Scripps to demonstrate the properties of the monoclonal antibodies to Factor VIILRP reported in the Meyer abstract and in two other abstracts, all of which related to the preparation of such monoclonals. On the ground that the difficulty of obtaining the monoclonal antibodies made the examiner’s request “an impossible burden,” Scripps withdrew claims 24 through 29 without prejudice. Reissue File History at 00419. Genentech raised before the PTO the claim of inequitable conduct it asserts here. The PTO Office of the Assistant Commissioner rejected the claim, finding that there was “no clear and convincing evidence of a violation [by Scripps] of the duty of disclosure through bad faith or gross negligence, or of fraud.” Reissue File History at 00517. B. Materiality Although the analysis to determine materiality has not been clearly articulated, the Federal Circuit appears to have adopted as the “appropriate starting point” the standard of PTO Rule 56, 37 C.F.R. § 1.56. J.P. Stevens, 747 F.2d at 1559; American Hoist, 725 F.2d at 1363. That rule states that persons involved in the preparation or prosecution of a patent application have a duty to disclose to the Office information they are aware of which is material