Patent Not Invalidated by Earlier Possession of the Invention by Others Who Did Not Appreciate What They Had

Case: Invitrogen v. Clontech, No. 04-1039, 04-1040 (Fed Cir. 11/18/05)

The One Sentence Summary: The panel reversed summary judgment of invalidity based upon a prior conception and later reduction to practice under 35 U.S.C. § 102(g) when a jury could conclude that the earlier inventors had not appreciated what had been invented.

What They Were Fighting About: Invitrogen owned patents for mutant reverse transcriptase (RT) with no RNase H activity - this enzyme is an effective tool for cloning DNA. Invitrogen reduced the invention to practice on January 27, 1987. Two other researchers at Columbia, Goff and Tanese, had isolated mutant RT in 1984, but did not confirm that the mutants lacked RNase H activity until March 1987 when a more sensitive test became available. The district court held that Goff had conceived the invention first and diligently reduced it to practice, after which Invitrogen consented to entry of final judgment of invalidity under 35 U.S.C. § 102(g).

Federal Circuit Holdings:

• Clontech had the burden of proving with clear and convincing evidence that Goff had conceived of the invention before Invitrogen, and diligently reduced it to practice.
• Conception requires appreciation. Accidental creation of the invention without appreciation of what has been created is not conception. The invention goes to the person who first realizes the invention and can describe it to others.
• In order to declare a patent invalid under § 102(g), the accused infringer must demonstrate prior conception with objective corroboration of when the prior inventor understood the invention.
• Clontech's expert improperly made conclusory statements that Goff had conceived of the invention in 1984, but did not back it up with explanations of the underlying notebook entries. Attorney argument explaining the notebook entries without expert backup was insufficient on summary judgment.
• The patent sufficiently enabled the invention although it described only one method of achieving the mutations. Alternate methods of making mutants that were known to one of skill in the art without undue experimentation were also within the scope of the invention when the claims were not limited to a single method.
• The patent claims provided a sufficient written description under 35 U.S.C. § 112 without providing DNA sequences of RT because the sequences were well known in the art.
• The district court properly construed the claims in granting partial summary judgment of infringement. Arguments in the parent application about different claim language did not create an estoppel as to different but similar claim language in the later application.
• Summary judgment was proper despite a conflict in expert testimony as to interpretation of gel assays when there was no support for the position taken by defendant's expert.