Enzo Biochem Inc. v. Applera Corp., No. 2014-1321, 2015 U.S. App. LEXIS 4064 (Fed. Cir. Mar. 16, 2015) (Prost, CJ.) (Newman, J., dissent). Click Here for a copy of the opinion.
Applera appealed from the district court's claim construction that led to a jury verdict that Enzo's U.S. patent No. 5,449,767 was infringed. The claims of the '767 patent are directed to an oligo- or polynucleotide probe where the nitrogenous base "B" is covalently attached to a chemical moiety "A." Claim 1 specifies that moiety A "comprises at least three carbon atoms and represents at least one component of a signaling moiety capable of producing a detectable signal." A is attached to B in a way that "does not substantially interfere with formation of the signaling moiety or detection of the detectable signal."
The district court construed "at least one component of a signaling moiety" to mean that A can be directly or indirectly detected, i.e., A can be the whole signaling moiety and detectable by itself, or ther signaling moiety can require a compound in addition to A in order to be detectable. On appeal, the Federal Circuit construed "at least one component of a signaling moiety" to mean "the signaling moiety is composed of multiple parts" because "component in and of itself indicates a multipart system." In addition, the plain reading of the accompanying phrase "does not substantially interfere with formation of the signaling moiety" indicates that "A" is not the whole signaling moiety, "as the claimed compound does not include a formed signaling moiety."
The court pointed out that throughout the specification, A was described as "being capable of forming a signaling moiety only in conjunction with other chemicals." In addition, the background section of the specification described how A forms a signaling moiety upon interaction with proteins such as avidin and antibodies. Furthermore, the specification only discussed direct detection – radioactive labeling – to explain that indirect detection is a superior method. Based on the specification, the court concluded that the claims only encompass indirect detection.
The court also disagreed with the district court's reliance on claim differentiation. Since Claim 1 is limited to indirect detection by its own plain meaning, the court concluded that "it would be inappropriate to use the doctrine of claim differentiation to broaden claim 1 to include a limitation imported from a dependent claim, such as direct detection." Because the district court erred in its claim construction, the Federal Circuit vacated the finding of infringement and remanded.
Dissenting form the majority opinion, Judge Newman argued that "[t]he rules of grammar and linguistics ... do not establish that 'at least one' means two or more." In addition, Applera's expert had conceded during cross examination that Example 9 in the specification "could involve direct detection." Judge Newman argued that these findings of facts should be given appropriate deference. She believed that the district court neither committed error of facts nor law in its findings and conclusions, and therefore there were no grounds for reversal.
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