TFF Ultrafiltration Diafiltration Calculator
Bioprocess Downstream Purification: Calculate transmembrane pressure (TMP), concentration factor (VCF), gel polarization flux, diafiltration buffer volume, and process time.
Feed Stream & Membrane Area
Process Hydraulics & Clearance Output
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Biopharmaceutical Tangential Flow Filtration (TFF)
Crossflow ultrafiltration sweeps the membrane surface continuously to prevent fouling while concentrating macromolecular biologics and exchanging formulation buffers.
1. Transmembrane Pressure (TMP)
The primary driving force for solvent transport across the semi-permeable membrane is:
TMP = ( P_feed + P_retentate ) / 2 - P_permeate
Maintaining TMP in the pressure-dependent linear regime prevents compaction of the protein gel layer.
Frequently Asked Questions
What is the role of Tangential Flow Filtration (TFF) in monoclonal antibody (mAb) manufacturing?
TFF (often using 30 kDa regenerated cellulose membranes) performs the final formulation step in bioprocessing: ultrafiltration (UF) concentrates the purified protein up to target subcutaneous delivery concentrations (e.g. 50–150 g/L), followed by diafiltration (DF) to exchange chromatography elution buffers into final formulation excipient matrices.
What causes permeate flux decline during protein ultrafiltration?
As water and buffer pass through the membrane, retained protein molecules accumulate at the membrane surface, creating a concentrated boundary layer. This concentration polarization phenomenon forms a viscous "gel layer" whose hydraulic resistance limits flux according to the film model: $J = k \ln(C_{gel} / C_b)$.
How many Diafiltration Volumes (DV) are typically required for buffer exchange?
For a freely permeable small-molecule salt or solvent (sieving coefficient $S = 1.0$), remaining impurity fraction decays exponentially: $C / C_0 = \exp(-DV)$. 5 diavolumes clears 99.3% of salts, while 6 to 7 diavolumes achieves >99.7% buffer exchange.