Functional Claims That Erroneously Recite The Claimed Function Are Vulnerable To Narrow Claim Construction And Invalidity

Bayer CropScience AG v. Dow AgroSciences LLC

Addressing the negative consequences of poor or erroneous claim drafting, the U.S. Court of Appeal for the Federal Circuit affirmed a narrow interpretation of a functional claim and a grant of summary judgment of non-infringement in favor of the defendant, finding that a narrow description of one species does not support a broader construction of the genus. Bayer CropScience AG v. Dow AgroSciences LLC, Case No. 13-1002 (Fed. Cir., Sept. 3, 2013) (Taranto, J.).

Bayer filed a patent application with claims directed to an enzyme that, when genetically incorporated into plants, could make them resistant to the herbicide 2,4-D. According to the application, the enzyme catalyzed the breakdown of 2,4-D into something harmless in plants. As a result, the 2,4-D herbicide could be used to destroy weeds with no adverse effects on the genetically engineered plants. The application described the enzyme as having a 2,4-D monooxygenase