The US Court of Appeals for the Federal Circuit reversed a district court’s denial of a motion for judgment as a matter of law (JMOL) of noninfringement, finding that the jury’s infringement findings were unsupported by sufficient evidence and that the district court had improperly delegated claim construction to the jury. Laboratory Corp. of America Holdings v. Qiagen Sciences, LLC, Case No. 23-2350 (Fed. Cir. Aug. 13, 2025) (Lourie, Dyk, Cunningham, JJ.)

Laboratory Corp. of America Holdings (LabCorp) holds two patents with substantially overlapping specifications, both generally directed to methods for preparing DNA samples for sequencing and enrichment techniques aimed at enabling whole-genome sequencing. LabCorp initiated litigation alleging that various Qiagen Sciences kits containing materials used in DNA sample preparation for sequencing infringed its patents. During claim construction, the district court construed several patent terms as follows:

• In the first patent, “second target-specific primer” means a single-stranded oligonucleotide with a 3’ portion that specifically anneals to a portion of the known target nucleotide sequence in the amplicon from step (b), and a 5’ portion identical to a second sequencing primer.
• Also in the first patent, “second adaptor primer” refers to a nucleic acid molecule containing a sequence identical to part of the first sequencing primer and nested relative to the first adaptor primer.
• In the second patent, “target-specific primer” is defined as a primer sufficiently complementary to the target to enable selective annealing and amplification, without amplifying non-target sequences in the sample.

The jury found that Qiagen infringed the first patent under the doctrine of equivalents and willfully and literally infringed the second patent. The jury awarded damages accordingly. The district court denied Qiagen’s renewed motion for JMOL to reverse the damages and the jury’s findings of infringement and validity, and its alternative request for a new trial. Qiagen appealed.

Qiagen raised two noninfringement arguments regarding the first patent, and the Federal Circuit agreed with both. First, the Court held that it was error to allow the jury to apply “plain meaning” and equate a sequence being “identical to another” with being “identical to a portion” of another. Specifically, Qiagen’s accused second target-specific primer (Sample Index Primer, or SIP) was 19 nucleotides long while the second sequencing primer (Read2 primer) was 34 nucleotides. The fact that they shared an overlapping sequence did not make them identical.

Although the district court had treated “identical” as a factual issue for the jury, the Federal Circuit, citing its 2008 decision in O2 Micro Int’l Ltd. v. Beyond Innovation Tech., found that this was a claim construction matter that should not have been left to the jury. The term “identical” must be given its full meaning under claim construction and cannot be interpreted as “identical to a portion.” The Court emphasized that the specification and claims distinguished between full and partial identity: The second target-specific primer must be “identical to” the second sequencing primer while the adaptor primer need only be “identical to a portion” of the first sequencing primer. This difference [...]

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