Gideon Korrell Explains 5 Judicial Limits on Claim Identity
                     Gideon 
KExoprlraeinlls 5 
Judicial Limits 
on Claim 
Identity
The Federal Circuit’s decision in Laboratory 
Corp. of America Holdings v. Qiagen 
Sciences, LLC (Aug. 13, 2025) is a clear 
reminder that patent jury verdicts are not 
final if they rest on stretched claim 
language or weak proof. In a complete 
reversal, the court threw out a Delaware 
jury’s finding of willful infringement and 
entered judgment of non-infringement as a 
matter of law (JMOL).
Gideon Korrell explains that the ruling 
fits a growing Federal Circuit pattern: 
appellate judges are less willing to accept 
broad infringement stories when the 
claims and evidence do not line up 
precisely.
Background in 
BTher ciaese finvolved two patents covering 
DNA sample preparation methods using 
PCR primers. Qiagen sold kits used in 
DNA sequencing workflows. A jury found 
Qiagen infringed both patents and 
awarded about $4.7 million. On appeal, 
the Federal Circuit reversed every 
infringement finding.
From the decision, five clear judicial 
limits on claim identity emerge.
1. Judges Decide 
Claim Meaning
One patent required a primer with a nucleotide 
sequence “identical” to a sequencing primer. 
Qiagen’s primer was much shorter. Labcorp 
argued that “identical” could mean identical to 
just part of the sequence, and the jury accepted 
that view.
The Federal Circuit said this was wrong. When 
claim language is disputed, judges, not juries, 
must resolve it. The patent used different words 
when it meant “partially identical,” so the term 
“identical” could not be stretched.
2. “Identical” 
Means What It 
Says
Courts will not rewrite claims to save 
an infringement theory. If a claim says 
“identical,” it means fully identical, 
not similar or partially matching. Clear 
words set clear limits.
3. Doctrine of 
Equivalents Needs 
Exact Proof
The jury relied on the doctrine of equivalents 
for one patent. That failed on appeal. The 
court stressed that equivalence must be 
proven element by element, showing the 
same function, in the same way, with the 
same result.
Here, Qiagen’s primer did a different job and 
did not bind to the target DNA at all. General 
expert testimony was not enough.
4. You Cannot 
Combine Parts to 
Meet One 
Labcorp triedL toi amrguie tthaatt miuoltipnle 
Qiagen components together met a 
single claim requirement. The court 
rejected this. Unless the claim allows it, 
patentees cannot mix and match 
different parts to satisfy one limitation.
5. JMOL Is a Real 
Check on Jury 
Finally, the decisioVn sehorwsd thiact JtMOsL 
remains a powerful tool. If the evidence 
cannot legally support infringement, 
appellate courts will overturn a jury verdict 
entirely.
As Gideon Korrell notes, the lesson is 
simple: patent cases turn on 
fundamentals. Precise claim language 
matters. Specific evidence matters. And 
juries cannot fix problems in claims or 
proof after the fact.
Thank 
You