Bovine Serum Albumin

Serum albumin is used in different molecular biology applications, e.g. as an inert protein stabilizer for stock solutions of enzymes and of proteins of interest. In such applications, it is therefore important for the BSA to be protease free, to maintain the integrity of the protein or the enzyme of interest.

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

Derived from New Zealand source serum

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.