In Agilent Technologies, Inc. v. Affymetrix, Inc., No. 08-1466 (Fed. Cir. June 4, 2009), the Federal Circuit reversed the district court’s affi rmance of a Board decision awarding priority to Affymetrix, Inc. for claims covering techniques for performing millions of genetic analyses on a small fl uid sample.

As a preliminary matter, the Court determined which specifi cation to consult when construing a copied claim whose written description is challenged in an interference. In so doing, the Court resolved the apparent confl ict between In re Spina, 975 F.2d 854 (Fed. Cir. 1992), and Rowe v. Dror, 112 F.3d 473 (Fed. Cir. 1997). In this case, where the PTO must assess whether both parties have a right to claim the same subject matter, the claim construction analysis properly occurred in the context of the specifi cation from which the claims were copied. See full summary below.