The Evolving Application of the Written Description Requirement to Biotechnological Inventions

38 Pages Posted: 9 Jul 2009


A United States patent must provide a "written description" of the invention claimed therein. In its earliest implementation, a patent's written description fulfilled a notice function of putting the public in possession of the boundaries of the patentee's property right. Under modern practice, that notice function is performed by the claims of the patent. In 1967, the Court of Customs and Patent Appeals (CCPA) breathed new life into the written description requirement of section 112 of the Patent Act by applying it for a different purpose, that of ensuring "support" for claims first presented or substantively amended after a patent application has been filed. The court viewed written description compliance as a means of ensuring that the patent applicant had actually invented the later-claimed subject matter as of the earlier filing date of the application. The CCPA and its successor, the Court of Appeals for the Federal Circuit, repeatedly recognized that the manner in which the written description was provided was not critical, so long as those of ordinary skill would understand the newly-claimed subject matter to be fairly within the patentee's original contribution.

Written description jurisprudence significantly diverged from these principles with the Federal Circuit's 1997 decision in Regents of the University of California v. Eli Lilly. In Lilly, the court applied the written description requirement to claims originally filed in a pioneering University of California patent application directed to the recombinant production of insulin, and held that the written description requirement is not satisfied for claims to DNA absent an express disclosure of nucleotide sequence. The Lilly decision may profoundly limit the scope of protection available for new gene inventions; viewed in tandem with contemporaneous Federal Circuit decisions interpreting the enablement requirement of section 112 , it represents the latest advance in an ominous trend towards imposition of uniquely heightened patentability requirements for biotechnological inventions. Lilly aptly illustrates the increased widening of the gulf between the norms of the business and scientific communities and the U.S. patent system, as users of the latter come to understand that the patent system no longer reflects the realities of scientific contribution.

Keywords: United States patent law, U.S. patent system, written description requirement, written description of the invention, new matter, possession, priority, biotechnological inventions, DNA, Regents of the University of California v. Eli Lilly, Court of Customs and Patent Appeals, CCPA, Federal Circuit

Suggested Citation

Mueller, Janice M., The Evolving Application of the Written Description Requirement to Biotechnological Inventions. Berkley Technology Law Journal, Vol. 13, 1998, U. of Pittsburgh Legal Studies Research Paper, Available at SSRN:

Janice M. Mueller (Contact Author)

Chisum Patent Academy ( email )

951 Delong Road
Lexington, KY 40515
United States
8553244786 x2 (Phone)


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