Bovine Serum Albumin (BSA) is a globular non-glycosylated protein that encompasses structurally distinct domains (I, II, and III) with two sub-domains, A and B within each domain. Structurally, BSA is an α-helical protein with 17 cysteine residues.

Bovine Serum Albumin has been used:

• as a component of the minimal liquid medium to culture Porphyromonas gingivalis strains
• as a standard protein to quantify microsomes homogenate using Bradford method
• as a blocking agent in enzyme-linked immunosorbent assay (ELISA) of fecal lactoferrin

Bovine Serum Albumin (BSA) is widely used in drugs and antibody delivery. It also finds applications in nanoparticle preparations and is useful in targeting tumor tissues. BSA is non-immunogenic and non-toxic. It also shows binding with metal ions.

Certain conformational and primary-sequence epitopes of BSA are suspected allergens in human beef and milk allergies.

Prepared using heat shock fractionation

Serum albumin may be referred to as Fraction V. This naming convention is taken from the original Cohn method of fractionating serum proteins using cold ethanol precipitation. Serum albumin was found in the fifth ethanol fraction using Cohn′s method. Since then, the term "Fraction V" has been used by some to describe serum albumin regardless of the method of preparation. Others have used this term to describe serum albumin purified by ethanol fractionation methods that have been highly modified since the original Cohn method was described. Sigma-Aldrich manufactures and distributes serum albumins purified from a variety of primary methods including the true Cohn fractionation method, modified ethanol fractionation methods, heat shock and chromatography. Additional purification steps may include crystallization or charcoal filtration.