Separation of proteins of nearly the same size but having different isoelectric points by convective electrophoresis

A method for separating proteins of nearly the same size but having different isoelectric points is presented. The method used is convective electrophoresis, which is based on the simultaneous effects of diffusion, electrical migration and opposing convective flow on the transport of proteins through a porous membrane. The pairs of model proteins used in this study were cytochrome c-lysozyme and human serum albumin-haemoglobin. The obtained results show that with a careful adjustment of pH these proteins can be separated by a continuous manner, and no coupling of protein fluxes could be detected in either case.