Concentration of proteins in the free‐flow electrophoretic apparatus

Abstract

AbstractProtein concentration using step pH and conductivity gradients in a free‐flow electrophoretic apparatus is described. The experiments were carried out in a vertical planar 36.5 × 5.0 × 0.05 cm separation chamber with 48 channels both at the inlet and outlet. The gradients were generated by injecting a 2.5 mM borax solution (pH 9.2, conductivity = 0.5 mS) into the chamber via channels No. 1–12 counting from the cathode, and 0.45 M boric acid (pH 4.3, conductivity = 0.025 mS) together with the protein to be concentrated via the remaining channels. The gradients were suitable for the concentration of the proteins with isoelectric points ≥ pH 7.0 (human immunoglobulin G, bovine hemoglobin). From mixtures of hemoglobin and albumin, the latter was removed during concentration. The protein concentration of the starting solution does not affect the results of concentration. At constant current of 30 mA and a residence time of 45 s, the proteins were concentrated at a rate of 400 ml of starting solution per hour with a maximum concentration factor of 10.