The Six Steps of Tangential Flow Filtration (TFF)

Thorough preparation is essential to ensure a successful TFF process. Pre-filter your sample to remove particulate sand protect the membrane from clogging. Prime the system with buffer to eliminate air and stabilize the membrane. Selecting the correct membrane type and pore size ensures precise separation of biomolecules.

Careful sample loading sets the foundation for effective filtration. Introduce your clarified sample into the feed reservoir, ensuring even flow into the system. Start the pump at a low flow rate to prevent pressure surges and ensure proper circulation. Monitor transmembrane pressure (TMP) to maintain performance and protect your sample.

Filtration is the heart of TFF, where the membrane separates biomolecules by size. Microfiltration membranes(≥ 0.1 microns) remove cells, debris, and large molecules while retaining proteins while ultrafiltration membranes (< 0.1 microns) concentrate proteins, retaining larger molecules and allowing smaller ones to pass.

Hollow fiber membranes filter as the feed flows throughfibers, while cassette membranes utilize stacked layers to achieve separation.

As filtration progresses, the permeate, containing smaller molecules, flows through the filter, while the retentate, with larger molecules, recirculates into the feed reservoir. This continuous loop ensures maximum separation efficiency, effectively removing smaller molecules while preserving valuable biomolecules. The recirculation process helps maintain consistent filter performance and prevents buildup on the filter surface, promoting steady, reliable operation throughout the filtration cycle.

When additional purification or buffer exchange is required, diafiltration offers a powerful solution. Add fresh buffer to the feed reservoir while maintaining the system’s total volume. This step removes unwanted salts or exchanges buffers, leaving your target biomolecule concentrated and purified.

Recovery is the final critical step in TFF, where your concentrated biomolecule is carefully collected. Use sterile tools and containers to preserve integrity and minimize contamination. For added safety and purity, pass the product through a sterilizing-grade filter before transferring it to storage or downstream processing.