Separation of biotin labeled proteins from their unlabeled counterparts using immobilized platinum affinity chromatography

A stationary phase selective for biotin labeled proteins has been developed by immobilizing platinum(II) ions to a polyacrylamide gel. Bovine serum albumin (BSA) and biotin labeled BSA (BSA-Biotin) have been applied individually to a packed column containing the modified gel. At pH 4.8 using column superficial velocities of 1.0 and 0.25 cm/min respectively, 40% and 73% of the applied BSA-Biotin were bound to the activated gel while no unconjugated BSA was bound. A 1.0 M imidazole-HCl solution at pH 7 was successfully used to elute bound BSA-Biotin, indicating that binding to immobilized Pt(II) is reversible.