Transferrin less the iron molecule. Like transferrin, apotransferrin has a physiological role in the transportation and distribution of iron among the body organs. It is also an important transport factor used in defined culture media. Purified to have less than 0.02 mg iron per gram of transferrin. Each human transferrin molecule has the ability to carry two iron ions in the ferric form (Fe3 ). Dissolves in water at 10 mg per ml. Prepared from plasma shown to be non reactive for HbsAG, anti-HCV, anti-HBc, and negative for anti-HIV 1 & 2 by FDA approved tests. Total protein determination by the Lowry method. >95percent pure and shows only one major band corresponding to the molecular weight of Transferrin by SDS-PAGE. Add deionized water to original volume, aliquot and freeze unused portion.