For concentration and diafiltration of the target product using tangential flow filtration (TFF), the key objective is effective retention of the target molecule. A membrane with a nominal molecular weight cutoff (NMWCO) approximately one-third to one-fifth of the target protein’s molecular weight is generally recommended.
For clarification, the target species must pass through the membrane. A molecular weight cutoff five to ten times greater than the molecular weight of the target species, or higher, is generally selected. For example, for a 150 kDa target protein, a 30 kDa or 50 kDa cassette is typically appropriate, providing high retention while maintaining good flux.
LePure Biotech LeUltra^™ ultrafiltration cassettes are available in pore-size options tailored to customer's specific process requirements.

LeUltra^™ uses a self-sealing silicone housing made of soft silicone. When the cassette is installed in the holder, the holder plates compress the silicone housing to create a seal, so no separate silicone gasket is required. Some conventional cassette designs require an external silicone gasket at the distribution plates on both ends of the stack; these gaskets must be cleaned, sterilized, and replaced as needed.

The LeSiever^™ LFT-1010 supports five most common test methods—bubble point, diffusion flow, water intrusion, pressure hold, and enhanced testing—covering most filter integrity testing applications in pharmaceutical manufacturing.

Yes, the LFT-1010 incorporates an electronic records and electronic signatures (ER/ES) system.
Tamper-resistant records: The instrument automatically exports seven types of files, including audit trails and operation logs, in non-editable PDF format.
Electronic signatures: It supports two-level electronic signatures, including handwritten signatures, to meet the operational compliance requirements of 21 CFR Part 11.
Full traceability: The complete data chain—from test initiation and parameter setup to result determination—is retained to support deviation investigations and release review.

EU GMP Annex 1 (2023), Section 4.34, and General Chapter 9210 of the 2025 Chinese Pharmacopoeia explicitly require the disinfection process itself to be validated rather than relying solely on supplier reports.
Certificate of Analysis (CoA)/efficacy report: This demonstrates that the batch meets specifications under the manufacturer’s test conditions, but it does not demonstrate efficacy in the user’s cleanroom at the user’s concentration and contact time or on the user’s stainless-steel, PVC, or epoxy surfaces.
Purpose of user validation: Under worst-case conditions—including the lowest effective concentration, shortest contact time, and organic interference—standard strains and environmental isolates from the facility are used to demonstrate that the required microbial log reduction is achieved.