LAUSR

Abstract Tangential flow filtration (TFF) is a size-based separation method conventionally used for buffer exchange, concentration, pathogen removal, and for coarse purification. In this study, we use TFF for selective purification of proteins in their complexed form. This process was demonstrated to recover human serum albumin (HSA) in its complexed form from an artificially produced mixture of hemoglobin (Hb) and HSA and from plasma using an anti-HSA polyclonal immunoglobulin G (IgG) as the target-protein binding molecule (TPBM). Moreover, haptoglobin (Hp) in its complexed form was recovered from human Cohn Fraction IV using Hb as the TPBM. Hb-Hp was then partially dissociated with 5 M urea to yield Hp. In the experiments performed here, the TP-TPBM had purities >95%, but recovery was low with >50% for HSA-IgG and 10–15% for Hb-Hp. However, a simple mathematical model used to describe the TFF purification process showed that product recovery could be increased without loss of purity by introducing TFF filters with the same MWCO in series. Taken together, this study presents a new method for selective purification of proteins using TFF and simple mathematical models to describe and predict the performance of TFF systems.