Description Application Bovine serum albumin has been used- • as a component of PCR (polymerase chain reaction) mix • in the preparation of dissociated cortical neurons • during immunofluorescent labeling • as a component of Ca2+-free saline (containing collagenase, hyaluronidase and DNAse) used for bovine tissue digestion Packaging 1, 5, 10 kg in poly drum 10, 50, 100, 500 g in poly bottle Biochem/physiol Actions Certain conformational and primary-sequence epitopes of BSA are suspected allergens in human beef and milk allergies. Preparation Note 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.