Provisional Discretion: CAFC's Repeat Performance In Affirming Prosecution History Disclaimers

On February 14, 2025 the US Court of Appeals for the Federal Circuit ("CAFC") again invoked prosecution history disclaimer from a provisional-to-nonprovisional transition to limit the scope of claims to exclude subject matter not explicitly recited from the provisional in the nonprovisional. This disclaimer persists even where the nonprovisional incorporates the provisional by reference.

In DNA GenoTek, Inc. v. Spectrum Solutions LLC, No. 23-2017, the court addressed claim construction concerning a patent for a device that preserves nucleic acids in biological samples. The patent, U.S. Patent No. 10,619,187, includes claims describing a "reagent compartment" of the containment vessel in the device. The central issue on appeal was whether the district court's construction of this term as a "region or section of the containment vessel" improperly excluded a reagent compartment in a cap, which the Federal Circuit ultimately affirmed.