Bovine Serum Albumin

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

BSA is a known carrier of fatty acids (FA). Thus control over the specific FA′s for culture of cell lines is important, as different cell lines can be differentially sensitive to particular fatty acids. Fatty acid-free BSA thus is a useful tool for cell culture experiments where the specific fatty acid content must be tightly controlled, to allow researchers to use particular fatty acids specific to their cell lines. Fatty acid-free albumin also allows for optimal and maximum binding sites for adding specific fatty acids to use in cell culture. The use of FA-free BSA also mitigates concerns about endogenous FA′s potentially in non-FA-free BSA.

Bovine serum albumin (BSA) is a highly abundant plasma protein that assists in the regulation of the colloidal osmotic pressure of blood. BSA is used in many different applications, such as cell culture, immunochemistry, and protein quantitation.

This BSA product is specifically tested for very low FA content / fatty acid free status.

Often referred to as Cohn fraction V; this product is prepared by a modified method of the Cohn cold ethanol fractionation method.

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.