Federal Circuit Patent Watch: District Court Errs by Turning a Matter of Claim Construction over to the Jury to Decide and by Allowing the Jury to Conclude “Identical” Could Mean “Identical to a Portion”

Federal Circuit Patent Watch: District Court Errs by Turning a Matter of Claim Construction over to the Jury to Decide and by Allowing the Jury to Conclude “Identical” Could Mean “Identical to a Portion”

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Precedential and Key Federal Circuit Opinions

1.  LABORATORY CORPORATION OF AMERICA HOLDINGS v. QIAGEN SCIENCES, LLC [OPINION] (2023-2350, 08/13/2025) (Lourie, Dyk, Cunningham)

Lourie, J. The Court reversed the district court’s denial of judgment as a matter of law of noninfringement.  

First, the Court held that the district court erred in denying JMOL of noninfringement by allowing the jury to conclude that “identical” could mean “identical to a portion.” It was error for the district court to turn a matter of claim construction over to the jury to decide as a factual dispute. As a matter of claim construction, “identical” cannot mean “identical to a portion” because “identical” means the same. Both the specification and claims differentiated the two terms according to their degree. Where two claim terms differ by a matter of degree, perhaps by use of a modifier for one term and not the other, a proper construction should give effect to that difference. Reading the modifier, “a portion,” into the unmodified term “identical” would render the modifier language superfluous.  Thus, “identical to a portion” cannot have the same degree of claim scope as “identical.”

Second, the district court erred in denying JMOL of noninfringement under the doctrine of equivalents because no reasonable jury could have found that the accused feature satisfied the claim limitation. The Court rejected the expert testimony as not exceptional and not rising to the level of particularized testimony and linking argument showing substantial similarity between the accused products and asserted claims in function, way, or result.  

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