Purity ≥99% by SDS-PAGE, MW: 66.5 KDa. Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca2+, Na+, K+, fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloidal osmotic pressure of blood. It is a major zinc transporter in plasma, typically binds about 80% of all plasma zinc.