General description
Bovine serum albumin is a protein which has a key role in
regulating blood colloidal osmotic pressure. A water-soluble protein composed
of 583 amino acids,[1][2] BSA has a calculated molecular weight of 66,430
Daltons. Six α-helices form three homologous domains of BSA. Depending on pH,
BSA undergoes reversible conformational isomerization. The native structure of
the protein becomes reactive and flexible on heating.[3]
This BSA product is specifically evaluated and tested for the following
properties:
- Very
low protease content / protease-free
- Very
low fatty acid content / fatty acid-free
Protease-free BSA is especially useful for applications like:
- Enzyme
assays
- Protein-based
assays
- Protease-sensitive
techniques that include:
a. Enzyme immunoassay (EIA)
b. Nucleic acid hybridization
c. Radioimmunoassay (RIA)
Application
Bovine Serum Albumin has been used:
- as a
constituent of medium used for the differentiation of human pluripotent
stem cells[4]
- in
enzyme-linked immunosorbent assay (ELISA) and sandwich ELISA[5]
- to
permeabilize fetal cortical cells[6]
This A7030 BSA has specifically been used as a component of blocking buffer in
a peptide-based ELISA assay for analysis of COVID-19 / SARS-CoV-2 samples (Poh,
C.K. et al., Nat. Commun., 11(1), 2806
(2020)).
Biochem/physiol Actions
Certain conformational and primary-sequence epitopes of BSA
are suspected allergens in human beef and milk allergies.
Features and Benefits
- Heat
shock fractionated
- Protease-free
- Fatty
acid-free
- Essentially
globulin-free
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.
