IN RE: CHROMACODE LITIGATION

Background

The patents concern biochemical tests that detect specific genetic sequences in samples using fluorescent signals. The parties’ patents address multiplexing, or detecting multiple targets in one sample, by using colors and combinations of light signals.

ChromaCode, Inc. originally sought a declaration that it did not infringe Bio-Rad Laboratories, Inc.’s ’128 and ’154 Patents. Bio-Rad asserted infringement counterclaims. In a related action, ChromaCode and the California Institute of Technology asserted that Bio-Rad infringed the ’051, ’170, and ’921 Patents. The cases were later consolidated. The parties asked the court to construe, meaning determine the legal meaning of, ten terms across the five patents.

Claim Constructions

1. “Digital amplification assay” (’128 Patent): The court held that the term is a limiting part of the claims and construed it as an assay in which targets are partitioned and amplified and digital information about whether the targets are present or absent is collected. The court rejected a narrower construction that would have limited the claims to digital polymerase chain reaction methods.

2. “Average level[s]” and “levels” (’128 Patent): The court adopted their plain and ordinary meaning rather than defining them as a statistical measure of frequency.

3. “Calculating” and “calculated” (’128 Patent): The court held that “calculating” and “estimating” are interchangeable, and that “calculated” and “estimated” are likewise interchangeable as proposed.

4. “Each [of]” (’128 and ’154 Patents): The court adopted the plain and ordinary meaning and rejected ChromaCode’s proposed interpretation of “each” as “each and every one.”

5. Order of “plotting” and “determining” steps (’154 Patent): The court held that the steps do not have to be performed in the order written in the claim.

6. “Providing a sample solution volume ... comprising at least seven hybridization probes” and “contacting ...” (’051 Patent): The court found the claim indefinite. The claim first described a sample solution that already contained analytes and probes, then required contacting that solution with the probes. The court concluded that the specification and prosecution history did not resolve this inconsistency, and that the proposed meanings of “mixing” or “containing” did not cure the problem.

7. “Corresponds to the presence of a unique combination ...” (’170 Patent): The court found the claim not indefinite and adopted the plain and ordinary meaning. The court determined that the claim’s references to a sample and to droplets could be understood together because the sample was made into a mixture and then divided into droplets.

8. “Cumulative intensity signal(s)” (’051 Patent): The court construed the term as a signal representing the total intensity of light emitted by a given probe type.

9. “Cumulative [signal/intensity] measurement” (’051 and ’170 Patents): For the ’051 Patent, the court construed the term as the measurement of the cumulative intensity signals in the volume. For the ’170 Patent, it construed the term as the measurement of the cumulative intensity of the signals in the plurality of droplets.

10. “Non-degenerately,” “degenerate,” and “degeneracy” (’051 and ’921 Patents): The court adopted constructions describing “degenerate” and “degeneracy” as situations in which a legitimate result is not definitive because it can indicate more than one possible combination of analyte presence or absence. “Nondegenerately” means that a result cannot indicate more than one possibility.

Ruling

The court entered the claim-construction order and construed all ten disputed terms as set out above. The order did not decide whether either side ultimately infringed the patents. Judge Euim K. Lee signed the order dated July 22, 2025.