Separation of IgG from human plasma using thiophilic hollow fiber membranes

To replace conventional bioaffinity ligand like protein A or protein G, pseudobioaffinity ligands seem to be an interesting alternative for the purification of IgG. In this study, thiophilic ligand (T-gel) was immobilized on a copolymer of ethylene and vinyl alcohol (PEVA) based hollow fiber membrane to obtain an affinity support for the purification of IgG from human plasma. Microporous hollow fibers have been modified via divinyl sulfone activation and coupled by 2-mercaptoethanol (T-PEVA). The affinity module allowed the purification of IgG from human plasma with high efficiency (85% of IgG loaded were adsorbed) with a very small contamination of albumin (<1%). The enrichment was quite high (IgG/albumin) as shown by a final ratio of 39.3/0.27 before loading. The binding capacity could allow the separation of 1.5 g of IgG from human plasma with a functionalized membrane surface area of 1 m2. We tried to minimize sample preparation by decreasing the salt concentration, the sample dilution and by optimizing the rinsing and elution steps. This thiophilic derivatized hollow fiber module proved that it could be used as a very efficient tool for the purification of IgG provided that high concentration of salt was added.