isoelectric focusing (IEF)
A method of separating amphoteric molecules with minor differences in isoelectric points (pI). IEF can be used with several different enzyme systems including Phosphoglucose Isomerase (PGI), Erythrocyte Acid Phosphatase (EAP), Superoxide Dismutase (SOD) or Tetrazolium Oxidase (TO), Albumin (in conjunction with Western Blot), Mannose Phosphate Isomerase (MPI), Carbonic Anhydrase I (CAI) and Hemoglobin (Hb).