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Bovine Serum Albumin

heat shock fraction, pH 5.2, ≥96%

Albumin bovine serum, BSA, Bovine albumin
CAS Number:
EC Number:
MDL number:

biological source


Quality Level




lyophilized powder

mol wt

~66 kDa

purified by

heat shock fractionation


poly bottle of


USA origin


ELISA: suitable
blocking: suitable
electrophoresis: suitable
western blot: suitable




water: soluble (40 mg/ml)

UniProt accession no.

foreign activity

BT virus, none detected
VSV virus, none detected

storage temp.


Gene Information

bovine ... ALB(280717)

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General description

Bovine serum albumin (BSA) is a serum protein with a calculated molecular weight of 66,430 Daltons BSA consists of three domains with two subdomains under each, and is a α-helical, globular and non-glycosylated protein with 17-disulfide bonds.

BSA acts as a carrier protein for biomolecules like as fatty acids, amino acids, and steroids.


Bovine Serum Albumin has been used:
  • with primary antibodies to prevent non-specific binding in immunohistochemistry of heart sections
  • as a component of trypsin inhibitor solution
  • as a component of sterile sorting buffer for immunocytochemistry of common lymphoid progenitor (CLP) cells

Although we have not specifically tested this product in the following applications, several publications have cited use of A8022 in various applications such as:
  • Embryo culture (Dobrinsky, J.R. et al., Biol. Reprod., 55(5), 1069-1074 (1996))
  • Oocyte culture medium (Jung, Y.J., and Cheon, Y.-P., Dev. Reprod., 18(2), 117-125 (2014))
  • Western blotting (Chronopoulos, A. et al., Nat. Commun., 7:7, 12630 (doi: 10.1038/ncomms12630) (2016)

Biochem/physiol Actions

Bovine Serum Albumin is used in many applications, such as the following:
  • A transporter for drugs, hormones and fatty acids.
  • As a blocking agent in enzyme linked immunosorbent assay (ELISA) for preventing non-specific binding of antigens and antibodies to microtiter plates
  • BSA is a crucial component of cell culture media and favors embryonic stem cells (hESC) differentiation.
  • BSA shares structural features with human serum albumin. Its high solubility, low cost and purity and interaction with surfactants make it useful in the cosmetic and pharmaceutical industries.
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.

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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