dissenting.
This case presents two significant issues relating to the written description requirement one old and one new. I respectfully dissent from the majority’s decision on each of these issues and its decision to hold the claims of U.S. Patent No. 4,900,-659 (the “'659 patent”) invalid.
First, the majority, like the district court, holds that all claims fail to satisfy the written description requirement as a matter of law. It is well established that the written description requirement presents a factual issue. Our established precedent requires a determination whether one skilled in the art at the time the application was filed would understand the nature of the claimed invention from the written description. No adequate record for summary judgment has been made in this case on that issue, much less a record that establishes invalidity by clear and convincing evidence as a matter of law. Second, with respect to claims 4 and 6 the majority holds that a deposit in the American Type Culture Collection (“ATCC”) cannot be used to satisfy the written description requirement. This is a matter of first impression, but I suggest that the majority’s decision is both incorrect and unfortunate from the perspective of sound public policy.
1. All Claims
Claim 1 essentially claims nucleotide sequences which selectively hybridize to the DNA of N. gonorrhoeae as opposed to hybridizing to the DNA of N. meningitid-is. Claim 5 essentially claims a method of detecting N. gonorrhoeae by using the nucleotide sequence of claim 1 as a probe. Claims 1 and 5 may be characterized as genus claims, as the claimed nucleotide sequence is not limited to a particular species. The other claims of the patent (claims 2, 3, 4, and 6) depend from either claim 1 or 5. The specification discloses, in great detail, the implementation of well-known screening methods for isolating the claimed nucleotide sequences. '659 Patent, col. 4, 1. 46 — col. 12, 1. 65. Two embodiments of the claimed nucleotide sequences are described as having about 850 base pairs and one other embodiment is described as having about 1300 base pairs. The claimed sequences are defined by their selective hybridization to the DNA of six specifically identified strains of N. go-norrhoeae which are on deposit with the ATCC as opposed to hybridizing to the DNA of six specifically identified strains of N. meningitides on deposit with the ATCC.
The defendant-appellees sought to invalidate the claims of the patent for failure to satisfy the written description requirement. When moving for summary judgment on the issue of invalidity, they did not rely on any testimony from anyone of ordinary skill in the art.1 They relied purely on attorney argument to support their claim as to why the claims do not satisfy the written description requirement. The district court held as a matter of law based on its own examination of the text of the patent that the patent was invalid for failure to satisfy the written description requirement. The majority agrees with the defendants’ argument that the specification “is insufficient to meet the *1025requirement of § 112, ¶ 1 as a matter of law ...Ante at 1017.
We have repeatedly held, including in Eli Lilly, that “[w]hether a specification complies with the written description requirement of § 112, ¶ 1, is a question of fact .... ” Regents of the Univ. of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1566, 43 USPQ2d 1398, 1404 (Fed.Cir.1997), cert. denied 523 U.S. 1089, 118 S.Ct. 1548, 140 L.Ed.2d 695 (1998). Moreover, the sufficiency of the description is measured from the point of view of one of ordinary skill in the art as of the time the description is filed. Reiffin v. Microsoft Corp., 214 F.3d 1342, 1346, 54 USPQ2d 1915, 1917-18 (Fed.Cir.2000). In In re Alton, 76 F.3d 1168, 1174-75, 37 USPQ2d 1578, 1583-84 (Fed.Cir.1996), this court reversed a decision of the Patent and Trademark Office (“PTO”) Board of Patent Appeals and Interferences (“Board”) upholding an examiner’s rejection of Alton’s patent application for failure to comply with the written description requirement. Alton had submitted a declaration from one of ordinary skill in the art stating that one of ordinary skill in the art would have understood the specification as adequately describing the claimed invention. Id. at 1172-73, 76 F.3d 1168, 37 USPQ2d at 1581-82. The examiner gave little or no weight to this declaration, contending that it was “an opinion affidavit on the ultimate legal question at issue.” Id. at 1174, 76 F.3d 1168, 37 USPQ2d at 1583. We reversed because the examiner and the Board applied the wrong legal standard by viewing the declaration as addressing a question of law rather than a question of fact, and required the PTO to evaluate the expert’s affadavit as bearing on the factual issue. Id.
The majority here finds support for its approach in Eli Lilly. Eli Lilly, in departing from the general rule that an applicant satisfies the written description requirement by “conveying] with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the invention,” Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563-64, 19 USPQ2d 1111, 1117 (Fed.Cir.1991), and imposing a unique written description requirement in the field of biotechnology, is open to serious question. But even Eli Lilly does not sanction the approach taken here. Eli Lilly recognized, of course, that there are situations in which the written description is so deficient that it fails to satisfy the written description requirement as a matter of law. In Eli Lilly itself the patent claimed “2. [a] recombinant procar-yotic microorganism modified to contain a nucleotide sequence having the structure of the reverse transcript of an mRNA of a vertebrate, which mRNA encodes insulin,” U.S. Patent No. 4,652,525, col. 21, 11. 1-5, and “5. [a] microorganism according to claim 2 wherein the vertebrate is a human.” Id. at col. 22, 11. 3-4. The claimed “reverse transcript of an mRNA [also known as ‘cDNA’] of a vertebrate” was not described by sequencing. Instead, the patent simply named the cDNA and described the process that could be used for isolating it. We held:
The name cDNA is not itself a written description of that DNA; it conveys no distinguishing information concerning its identity. While the example provides a process for obtaining human insulin-encoding cDNA, there is no further information in the patent pertaining to that cDNA’s relevant structural or physical characteristics; in other words, it thus does not describe human insulin cDNA. Describing a method of preparing a cDNA or even describing the protein that the cDNA encodes, as the example does, does not necessarily describe the cDNA itself. No sequence information indicating which nucleotides constitute *1026human cDNA appears in the patent, as appears for rat eDNA in Example 5 of the patent. Accordingly, the specification does not provide a written description of the invention of claim 5.
Eli Lilly, 119 F.3d at 1567, 43 USPQ2d at 1405.
The patent here is quite different. It states that the claimed nucleotide sequences specifically hybridize to the DNA of particular strains of N. gonorrhoeae on deposit with the ATCC and not to the DNA of particular strains of N. meningi-tidis on deposit with the ATCC. The parties agree that this selective hybridization of the claimed sequences is indicative of a structure that is more complementary to the structures of the DNAs of the disclosed N. gonorrhoeae strains than to those of the N. meningitidis strains. As the majority correctly points out “Enzo may have derived three nucleotide sequences that exploit some region or regions of non-homology between N. gonor-rhoeae and N. meningitidis .... ” Ante at 1020. The majority discounts this description as merely functional, ante at 1018, 1020, but I view the description as identifying a structural difference between the DNAs of N. gonorrhoeae and N. meningi-tidis. The property of the claimed nucleotide sequences hybridizing to particular, known DNAs is a direct result of the structure of the nucleotide sequence. The degree of hybridization between a probe and a target depends on the degree of complementarity between the chemical structure between the probe and the target. To be sure, the sequences and the chemical structure of the targets were not disclosed in the specification, but the targets were not novel, and the “Background” section of the patent states that the degree of homology between the N. gonorrhoeae and N. meningitidis DNA targets was known to be between 80% to 93%. '659 patent, col. 2,11. 61-64. This indicates that the structure of the targets was at least somewhat known to those of skill in the art. Thus, by describing the degree of hybridization of the claimed nucleotide sequences, the specification may adequately describe the structure of the claimed sequences. At least one of ordinary skill in the art might so conclude. There has been no factual showing that one of skill in the art would not understand that the claimed invention is described by a written description of its hybridization-specific properties.2
In light of the appellees’ failure to make a factual showing supporting summary judgment, we should reverse the district court’s summary judgment of invalidity and remand to the district court for a factual finding, after a hearing, of whether one of ordinary skill in the art would consider the specification to describe the claimed invention.
2. Claims Jp and 6.
Claims 4 and 6, which depend from claims 1 and 5, respectively, provide an even more detailed written description. They are directed to the nucleotide sequences of particular deposited samples, *1027deposited with the ATCC. The samples are identified by their deposition numbers, ATCC 53409, ATCC 53410, ATCC 53411, and were deposited on January 9, 1986, twenty-one days before the patent application was filed. '659 patent, col. 13,11. 9-13.
Claim 4 depends from claim 1, and further limits claim 1 to “nucleotide sequences ... selected from the group consisting of: (a.) the Neisseria gonorroheae DNA insert of ATCC 53409, ATCC 53410 and ATCC 53411, and discrete nucleotide subsequences thereof, (b.) mutated discrete nucleotide sequences of any of the foregoing inserts that are within said hybridization ratio and subsequences thereof; and (c.) mixtures thereof.” '659 patent, col. 28, 11. 33-39 (first emphasis added).
Claim 6 depends from claim 5, and further limits claim 5 to a screening method using a polynucleotide probe in which the “polynucleotide probe is a composition selected from the group consisting of the Neisseria gonorrhoeae DNA insert of ATCC 53409, ATCC 53410 and ATCC 53411, and discrete nucleotide subse-quences thereof; and mutated discrete nucleotide subsequences of any of the foregoing inserts _” '659 Patent, col. 28, 11. 47-52 (first emphasis added).
On the face of it, a specification that describes the invention by reference to a deposit of a sample of the invention in a recognized depository is an ideal way of satisfying the written description requirement. The primary purpose of the statutory written description requirement is to provide notice to competitors and the public of the scope of the patent claims. The Supreme Court has stated that
The object of the statute is to require the patentee to describe his invention so that others may construct and use it after the expiration of the patent and “to inform the public during the life of the patent of the limits of the monopoly asserted, so that it may be known which, features may be safely used or manufactured without a license and which may not.”
Schriber-Schroth Co. v. Cleveland Trust Co., 305 U.S. 47, 57, 59 S.Ct. 8, 83 L.Ed. 34 (1938) (quoting Permutit Co. v. Graver Corp., 284 U.S. 52, 60, 52 S.Ct. 53, 76 L.Ed. 163 (1931)). Our predecessor court stated that “the ‘essential goal’ of the description of the invention requirement is to clearly convey the information that an applicant has invented the subject matter which is claimed.” In re Barker, 559 F.2d 588, 592 n. 4, 194 USPQ 470, 473 n. 4 (CCPA 1977), cert. denied 434 U.S. 1064, 98 S.Ct. 1238, 55 L.Ed.2d 764 (1978). A description by reference to the deposited sample provides a precise and unmistakably clear description of the invention that is accessible to the public.
However, the majority correctly points out that the written description requirement has a second purpose — to enable the PTO to conduct an examination of the patent application. The majority holds that reference to the deposited samples in claims 4 and 6 does not satisfy the written description requirement of 35 U.S.C. § 112 because “[a]n adequate description is necessary for proper examination of an application” and “[t]he examination of the application for patentability proceeds solely on the basis of the written description.” Ante at 1021. The majority concludes that “a deposit is not a substitute for a written description.” Ante at 1022. I think that reference to deposits is sufficient for proper examination of applications.
First, in the context of biotechnology inventions, the PTO has adopted regulations governing the deposit of biological materials. 37 C.F.R §§ 1.801 — 1.809. Those regulations provide inter alia that “[wjhere an invention is, or relies on, a biological material, the disclosure may in-*1028elude reference to a deposit of such biological material.” 37 C.F.R. § 1.802(a) (2001). Section 1.803 establishes criteria a depository must meet in order to be acceptable for the purposes of the PTO. When a deposit is made in an acceptable depository, “[tjhe examiner shall determine ... if a deposit is needed, and if needed, if a deposit actually made is acceptable for patent purposes.” 37 C.F.R. § 1.809(a) (2001) (emphases added). The regulations merely require that the specification contain “[a] description of the deposited biological material sufficient to specifically identify it and to permit examination.” 37 C.F.R. § 1.809(d)(3)(2001). When adopting § 1.809(d)(3), the PTO specifically rejected a suggestion that would have required an application to contain a specification that would “fully identify and describe the deposited material.” Deposit of Biological Materials for Patent Purposes, 54 Fed. Reg. 34,864, 34,874 (Aug. 22, 1989). In short, the PTO has made clear that applicants may take advantage of a biological depository, and contemplates that deposited material may be used for written description purposes. There is no necessity that the PTO actually examine the cell deposits when determining that the patent satisfies the written description requirement.
Second, the examiner did not here find the written description inadequate for examination purposes. If the examiner here had rejected the application for failure to satisfy the written description requirement and had insisted on a written description that set forth the gene sequencing, on an appeal from the Board we would have quite a different question. But the possibility that the PTO could require something more in the way of a written description should not cause us to reject cell deposits as satisfying the written description requirement when the PTO has concluded, as here, that the cell deposit is sufficient for written description purposes and the PTO’s own examination.
In the examiner’s first Office action the examiner recognized the importance of the deposited materials and required the applicant to assure public access to the microorganisms. The examiner stated:
The specification is objected to under 35 U.S.C. § 112, first paragraph, as failing to provide an enabling disclosure. Applicants are required to assure public access to the deposited microorganisms. The requirements are: The duration of the deposit be for 30 years from the date of deposit or for 5 years after the last request for the deposit at the depository or for the enforceable life of the U.S. patent whichever is longest. Also all of the other requirements of MPEP 608-01(p) Section C are in effect. It is also required that the organisms will be replenished should they become non-viable.
Claims 1-8 are rejected under 35 U.S.C. § 112, first paragraph, for the reasons set forth in the above objection to the specification.
The patentee did what the examiner required. In this Office action, the examiner rejected the claims under 35 U.S.C. § 112 for failing to provide an enabling disclosure. However, the examiner did not reject the claims for failure to comply with the written description requirement and eventually approved the application. And the examiner specifically addressed the applicant’s use of the depository, but did not object to the application on written description grounds. The PTO’s acceptance of the adequacy of the written description here reflects a determination by the PTO, pursuant to 37 C.F.R. § 1.809, that the deposited material was “acceptable for patent purposes,” including compliance with the written description requirement and that review of the deposit and a description in the specification by sequencing was *1029unnecessary for PTO examination. Nevertheless, the majority invalidates all claims of the patent on the same record that the PTO had before it.
The consequence of the majority’s approach, I think, is considerable unfairness to an applicant which, finding no statutory or regulatory bar to reliance on a cell deposit for written description purposes, and finding that the PTO itself is satisfied with reliance on a cell deposit, secures a patent that relies on a cell deposit only to have this court conclude after the fact that this reliance is impermissible. At this point it is far too late to amend the application, which was deemed satisfactory by the PTO. If the cell deposit were inadequate for public notice purposes, the majority’s approach would be quite appropriate. But where the only purpose served by our insistence on a better written description is to enable the PTO’s own examination, and the PTO itself was satisfied, we should not be second-guessing the PTO’s own judgment. Cf. Dethmers Mfg. Co. v. Automatic Equip. Mfg. Co., 272 F.3d 1365, 1379, 60 USPQ2d 1929, 1939 (Fed.Cir.2001) (Dyk, J., dissenting) (“[W]e are obligated by clear Supreme Court precedent to give deference to the PTO’s own interpretation of its regulations.”).
The practical effect of the majority’s holding that reference to the depository is insufficient to satisfy the written description requirement is to make description by reference to the depository impossible. This is quite inconsistent with the statutory and regulatory scheme.3
For these reasons, I respectfully dissent.
. Appellees apparently submitted a declaration from Dr. Philip Sparling, but concede here that they did not rely on this declaration when moving for summary judgment.
. The majority faults the specification for failing to describe the amino acid sequences of the targets, and points out that the patent itself acknowledges that the sequences of the targets were not determined. Ante at 1023. But the patent states the reason the sequences were not determined is because at the time of the filing of the application in 1986 "it would [have] take[n] 3,000 scientists one month to sequence the genome of one strain of Neisse-ria gonorrhoeae and one strain of Neisseria meningitidis.” '659 patent, col. 3, II. 43-46. I do not believe that the patent laws require such a Herculean effort on the part of the patentee when one of ordinary skill in the art might understand the nature of his invention from a simpler written description of it.
. Ironically, the majority raises no question about the use of the ATCC depository to describe the object of the invention to create a probe that specifically hybridizes to known strains of N. gonorrhoeae on deposit with the ATCC and not to particular strains of N. men-ingitidis on deposit with the ATCC.