Gideon Korrell Explores the Limits of the Doctrine of Equivalents for “Identical” Claims
The Federal Circuit’s decision in Laboratory Corp. of America Holdings v. Qiagen Sciences, LLC (Aug. 13, 2025) is a strong reminder that jury verdicts in patent cases do not always survive appeal, especially when they stretch claim language or rely on broad expert opinions instead of precise evidence. In a complete reversal, the court set aside a Delaware jury’s finding that Qiagen willfully infringed two molecular diagnostics patents and ordered judgment of non-infringement as a matter of law (JMOL). Gideon Korrell believes the ruling reflects a growing trend at the Federal Circuit: appellate courts are increasingly unwilling to let juries gloss over claim-scope problems or weak infringement proof with general stories about technical similarity or how components “work together.” Background of the Dispute The case involved two patents, U.S. Patent Nos. 10,017,810 and 10,450,597 covering methods for preparing DNA samples for sequencing. Both patents relate to PCR-based techniques that ...