The transferrins are a group of iron-binding glucoproteins migrating in the 3-globulin region on starch gel electrophoresis (Smithies and Hiller, i959). Commonly, there is a single iron-binding band called transferrin C, but faster (B variants) and slower (D variants) migrating bands are occasionally present. They are termed in order of electrophoretic mobility towards the anode Bo, Bo-i, B1, B...
