GoldBio BSA is a highly purified, lyophilized albumin, suitable for Westerns, enzyme systems, protein standards, hybridizations and as a protease-sensitive immunoassays.  It is also perfectly suitable as a nutrient in cell culture media, with low interference and backgrounds and is ideal for most standard molecular biology experiments.  BSA protein is a single polypeptide chain consisting of ~583 amino acid residues and no carbohydrates and is approximately 66 kDa in size.  Fraction V refers to the fifth fraction of the original Cohn purification of plasma proteins using cold ethanol precipitation and is still commonly used as a name for bovine serum albumin regardless of purification method.