Bovine Serum Albumin (also known as BSA or "Fraction V") is a serum albumin protein derived from bovine blood. It is often used as a protein concentration standard in lab experiments. The BSA protein is purified and fractionated through a certain heat-shock procedure, followed by extensive diafiltration and ion-exchange to remove other plasma proteins, lipids, and extraneous ions. BSA Protease Free (BSA FAF) is particularly suitable for applications with protease-sensitive protein components. BSA protein has numerous biochemical applications including ELISAs (Enzyme-Linked Immunosorbent Assay), immunoblots, and immunohistochemistry. It is also used as a stabilizer and cell growth supplement in cell and microbial cultures