IP Law Daily, PATENT—D. Del.: Summary judgment of non-infringement granted in cDNA dispute, (Nov 5, 2025)

By Kevin M. Finson, J.D.

Accused products did not, as a matter of law, infringe three asserted patents because they could not practice a claim limitation regarding the appending of tags to cDNA molecules at a time when it was undisputed that cDNA molecules did not yet exist.

A seller of products using reverse transcription of DNA was entitled to summary judgment of non-infringement of a competitor’s patents, the U.S. District Court in Wilmington has held. The accused products did not practice a claim term requiring multiple rounds of appending of tags to cDNA molecules, (Scale Biosciences, Inc. v. Parse Biosciences, Inc., No. 22-1597-CJB, (D. Del. Nov. 4, 2025)).

Scale Biosciences, Inc., a biotechnology company specializing in single-cell sequencing and molecular barcoding technologies, brought the infringement suit against Parse Biosciences, Inc., a competitor focused on combinatorial barcoding-based single-cell sequencing products. Roche Sequencing Solutions, Inc., the patent owner, granted Scale an exclusive license to the asserted patents.

Parse filed counterclaims alongside the University of Washington, alleging invalidity and non-infringement. Parse and the University were co-developers of Parse’s combinatorial barcoding platform and sought to clear their products of infringement liability.

Patent owner Roche Sequencing Solutions, Inc. and its exclusive licensee, Scale Biosciences, Inc. (collectively, Scale) brought suit against Parse Biosciences, Inc. and the University of Washington (collectively, Parse)., asserting infringement of four patents—U.S. Patent Nos. 10,626,442 (the ’442 patent), 10,982,256 (the ’256 patent), 11,512,341 (the ’341 patent), and 11,634,752 (the ’752 patent). On October 8, 2025, the court invalidated the '752 patent for lack of written description and enablement as a matter of law.

Parse counterclaimed for infringement of three patents—U.S. Patents Nos. 10,900,065 (the '065 patent), 11,168,355 (the '355 patent), and 11,427,856 (the '856 patent), all of which related to “[m]ethods of uniquely labeling or barcoding molecules within a cell, a plurality of cells, and/or a tissue[.]”Parse asserted that Scale infringed the asserted claims by making, selling, offering for sale, and using certain of Scale’s single-cell RNA sequencing kits, among other related kits and products (the “accused products”).

Presently before the court was Scale’s motion for summary judgment of non-infringement on the basis that the accused products “Indexed Reverse Transcription step” did not amount to a second “round” of “appending well-specific tags to cDNAs” as required by the asserted claims.

Claim construction. Scale suggested that the term “cDNA” be construed as “a biopolymer made of connected nucleotides, not any one separate nucleotide” and Parse did not offer an alternative construction. The court found that although there was some disagreement at oral argument, the parties eventually came to an agreement on what was effectively Scale’s proposed construction.

As to the term “appending,” the court also found that, despite some confusion at oral argument, the parties had ultimately agreed that it meant attaching one thing to another and it was used in the present tense.

Literal infringement. Applying the undisputed claim construction of “cDNA[]” and “appending,” the court analyzed infringement. The court found, based on the expert reports in evidence, that Indexed Reverse Transcription could not constitute an appending of tags to cDNAs because during reverse transcription a tag is attached to a single nucleotide, and there is not yet at that moment in time a cDNA molecule, which must consist of multiple nucleotides.

The court granted Scales’s motion for summary judgment of noninfringement.

The Case is No. 22-1597-CJB.

Judge: Burke, C.

Attorneys: Kelly E. Farnan (Richards, Layton, & Finger, PA) and Stephen S. Rabinowitz (Wolf, Greenfield, &Sacks, P.C.) for Scale Biosciences, Inc. and Roche Sequencing Solutions, Inc. Karen L. Pascale (Young Conaway Stargatt & Taylor LLP) and Chandrika Vira (Sterne, Kessler, Goldstein & Fox, PLLC) for Parse Biosciences, Inc. and University of Washington.

Companies: Scale Biosciences, Inc.; Roche Sequencing Solutions, Inc.; Parse Biosciences, Inc.; University of Washington

Cases: Patent DelawareNews