High-throughput processing of proteins using a porous and tentacle anion-exchange membrane

The immobilization of polymer chains containing a diethylamino (DEA) group on the pore surface of a porous hollow-fibre membrane is reported. This novel membrane can collect proteins at a high rate and high capacity because of convective transport and multi-layering of proteins. Overlapping of the breakthrough curves for different residence times of bovine serum albumin (BSA) solution demonstrates that the diffusional resistance of BSA to the DEA group anchored to the polymer chain was negligible. Membranes with a higher density of DEA groups exhibited a higher binding capacity for BSA. For example, a membrane with a DEA group density of 2.9 mol/kg had a BSA binding capacity of 490 g/kg, which was equivalent to eleven times the adsorption capacity of a monolayer. This vertical layering is due to holding of the BSA molecules in a tentacle-like manner by the graft chains extending from the pore surface towards the pore interior.