Within the 8-company assignee ranking captured here, one applicant leads with 7 records, well ahead of the fifth-ranked assignee’s 2 records. That gap means the field is not evenly spread — most of the claim language that matters for a freedom-to-operate review traces back to a single portfolio. Smaller filers, including university and named-inventor assignees, hold the remainder in small numbers, so a full landscape check still needs to cover them individually rather than assuming the leader’s claims cover everything.

US20250270539A1, filed by Genentech and published 2025-08-28, describes methods for combinatorial indexing of nucleic acids from single cells or nuclei, where at least two index sequences are incorporated into each cell’s nucleic acids so that pooled sequencing reads can be traced back to their cell of origin. It also covers methods for generating and sequencing libraries built from that indexed material. Anyone building a combinatorial-indexing step into a single-cell workflow should read this filing’s claims directly rather than relying on the abstract, since the abstract describes the method generally but the enforceable scope sits in the claim language.

It is thin by patent-landscape standards: only 11 published records sit in scope across an 11-year window, and the ranked assignee field has just 8 companies. The nucleic acid measurement side of the assay, IPC class C12Q, is heavily claimed at 90.9% of the 11 records, but protein readout (C07K, 18.2%) and combinatorial library methods (C40B, 9.1%) are comparatively open. A team entering on the protein-readout or library side has more room than one entering on the nucleic acid indexing side.