Description_x000D_ General description_x000D_ Bovine serum albumin (BSA) is a water-soluble serum protein, 583 amino acids in length, with a calculated molecular weight of 66,430 Daltons. Six a-helices form its three homologous domains. Depending on pH, bovine serum albumin undergoes reversible conformational isomerization. BSA native structure becomes reactive and flexible on heating._x000D_ BSA is a carrier protein for many biomolecules, such as fatty acids, amino acids, and steroids. For its carrier properties, BSA is also widely used in cell culture. BSA also serves antioxidant functions when used in cell culture._x000D_ Application_x000D_ Select the right albumin for your application with the Albumin Selection Guide_x000D_ Bovine Serum Albumin has been used in the solution prepared for digestion of tissues. It has been used as a blocking agent in cell spreading assay._x000D_ Because BSA is a well-known carrier of fatty acids (FA), control over the particular fatty acids used to culture cell lines is important, for cell culture lines which are sensitive to particular fatty acids. Fatty acid-free BSA is a highly useful reagent for such cell culture experiments, to allow researchers to use such BSA as a carrier for their specific fatty acids specific to their cell culture system. This mitigates potential risks to the cells from FA′s that might be present in non-FA-free BSA._x000D_ This BSA product is specifically tested for the following properties:_x000D_ • Fatty acid free / very low FA content_x000D_ • Low endotoxin level_x000D_ • Suitability to use in cell culture_x000D_ Packaging_x000D_ 1, 5 g in poly bottle_x000D_ Biochem/physiol Actions_x000D_ Certain conformational and primary-sequence epitopes of BSA are suspected allergens in human beef and milk allergies._x000D_ Features and Benefits_x000D_ • Tested for use in cell culture_x000D_ • Fatty acid-free_x000D_ • Low endotoxin_x000D_ • Cold ethanol fractionated_x000D_ Preparation Note_x000D_ Often referred to as Cohn fraction V; this product is prepared by a modified method of the Cohn cold ethanol fractionation method._x000D_ 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.