A method of preparative starch-gel electrophoresis

A convenient method has been developed for the recovery of protein components in high yield by continuous elution during starch-gel electrophoresis. A standard starch-gel mold was modified for this purpose by drilling two holes in the wall of the mold to allow a flow of buffer at right angles to the direction of electrophoretic migration. After an initial period of electrophoresis the section of starch gel between the holes was excised and the anodal wall of the trough formed covered with dialysis membrane. The trough was filled with polyurethane sponge and covered with a plastic sheet. Electrophoresis was then continued with a transverse flow of buffer which removed the proteins in the order of their electrophoretic mobility. This method has been employed in the isolation of human thyroxine-binding prealbumin and in the preparation of electrophoretically homogenous ¹³¹I-labeled thyroxine-binding pre-albumin and human serum albumin for turnover studies in man.