Patent Law: Examination Guidelines

National Law Journal at B7, January 2000

U. of Pittsburgh Legal Studies Research Paper Series

1 Pages Posted: 29 Sep 2009 Last revised: 12 Mar 2013

Multiple version iconThere are 2 versions of this paper


In this work, author Janice Mueller discusses the USPTO’s 1999 proposed examination guidelines for compliance with the written description requirement of 35 U.S.C. § 112 and the utility requirement of 35 U.S.C. § 101. While PTO guidelines do not have the force of law, they do impact the examination process. For practical purposes, the guidelines bind examiners and applicants. Mueller believes that the proposed written description guidelines’ requirement that examiners identify the “essential distinguishing characteristics” of a claimed invention, as part of applying the “possession” test, is problematic. Not only is the “essential elements” test an extra-statutory inquiry, but it may also trigger unforeseen prosecution history estoppels. The implementation of the utility guidelines will be particularly important for the patentability and interpretation of claims to expressed sequence tags (ESTs, short segments of genetic material) that include an open-ended “comprising” transition.

Keywords: written description requirement, utility requirement, ESTs, DNA, 35 U.S.C. § 112, 35 U.S.C. § 101, U.S. Patent and Trademark Office, USPTO, examination guidelines, patent Law, patent reform, possession test, essential elements test, Regents of the University of California v. Eli Lilly , Gentry Galle

Suggested Citation

Mueller, Janice M., Patent Law: Examination Guidelines. National Law Journal at B7, January 2000, U. of Pittsburgh Legal Studies Research Paper Series, 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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