Single-pass tangential flow filtration (SPTFF) concentrates a macromolecule solution by passing it once through one or more membrane stages, rather than recirculating it in a batch loop. It matters for patent purposes because the most-cited filing in this dataset, WO2019236811A1 and its US counterpart, claims a specific hybrid configuration where membranes of different molecular weight cutoffs are staged in series within a single pass. That specific staging is the element competitors need to design around, not the general concept of single-pass filtration.

This dataset’s assignee ranking covers four companies and all 14 records in scope — the leader holds 9 records, with the remaining three splitting the rest. Because the ranked list is short, describing it as a ‘top 50’ or similar would be misleading; it is the complete set the data endpoint returns for this search. Recent-year filing activity is thin across all four, with only one record attributed to any assignee in the latest year.

The clearest gap is C12N (microorganisms and genetic engineering), which appears in only 1 of the 14 records against 13 for C07K and 6 for B01D. That points to under-claimed territory around tying UF/DF process parameters directly to upstream cell-culture or expression-system characteristics, rather than treating concentration as a purely downstream physical step. Filing activity in India, Canada and Australia is also limited to a single record each, which is comparatively open ground relative to the WIPO/PCT and EPO filings.