One assignee leads with 108 of the 305 records in scope, well ahead of the fifth-ranked company at 11 records. That single filer’s position, combined with the top five collectively holding 67.2% of all records, means the field is concentrated rather than fragmented. Anyone assessing freedom to operate should treat that leader’s portfolio as the first and most important prior-art set to clear.

Filing activity peaked in 2021 at 55 records and had fallen to 33 by 2024, a 40% decline over that span, based on the most recent year with complete publication data. That decline likely reflects the core chemistry claims settling rather than falling interest, since publication lags filing by roughly 18 months and the newest years in any dataset are always undercounted. Read the 2025-2026 figures as provisional, not as evidence of a continued drop.

Closed linear DNA is a DNA format produced enzymatically in vitro, using a DNA polymerase to amplify a template and a protelomerase enzyme to convert it into a closed linear structure without bacterial fermentation. The earliest patents describing this process, including filings assigned to Touchlight, are the most-cited records in this dataset, which means later filers have repeatedly had to define their own claims against that prior art. Its prominence in the citation graph reflects how foundational those early claims became to the rest of the field, not that the technology itself is newer or more advanced than alternatives.