Evidence against the occurrence of artifacts due to carrier ampholyte-protein binding during isoelectric focusing

The formation of irreversible complexes between carrier ampholyte components and proteins was investigated by gel filtration of mixtures of proteins and radioactively labelled ampholytes. Experiments were performed both with purified proteins (albumin, ferritin, beta-glucuronidase) and with a complex mixture of proteins (serum); in no case was binding of ampholytes to proteins detected. Thus the results argue against the occurrence in isoelectric focusing of proteins of artifacts due to such complex formation.