Bovine Serum Albumin (BSA)

Points for attention in preparation.
Serum albumin can be called the "fifth component". The nomenclature rule is taken from the original Cohen method which uses cold ethanol precipitation to separate serum proteins. Serum albumin was found in the fifth ethanol fraction using the Cohen method. Since then, the term "fifth component" has been used to describe serum albumin, regardless of the method of preparation. Others have used the term to describe serum albumin purified by ethanol fractionation, which has been highly improved since the release of the original Cohen method. Abcone manufactures and distributes serum albumin purified from a variety of major methods, including true Cohn fractionation, improved ethanol fractionation, heat shock and chromatographic analysis. Other purification steps may include crystallization or charcoal filtration.

Biochemical / physiological behavior.
Some conformations and major sequence epitopes of BSA are suspected allergens in human allergy to beef and milk.