Jackson Immuno Research Inc.
specializing in secondary antibodies and conjugates

Bovine Serum Albumin

IgG-Free, Protease-Free Bovine Serum Albumin


Bovine Serum Albumin (BSA) is used extensively as a carrier protein to dilute antibodies and as a general protein blocking agent in immunoassays.

JIR Bovine Serum Albumin is verified to be IgG- and protease-free, alleviating many problems associated with commonly available preparations.

Note: Most commercial preparations of BSA, including some of the highest purity grades, contain contaminating bovine IgG that may become an antigen for cross-reacting secondary antibodies. This is particularly common when using anti-bovine IgG, anti-goat IgG (with the exception of bovine anti-goat IgG), anti-horse IgG, or anti-sheep IgG, but may occur with other antibodies that cross-react with bovine IgG. The result of these interactions may be loss of desired antibody activity, loss of antibody stability, and/or increased background.

Secondary antibody activity may be lost if the antibody is diluted in BSA that contains contaminating bovine IgG. Background may derive from sticky soluble immune complexes in the antibody diluent, or from bovine IgG found in a BSA blocking solution which becomes a target for labeled secondary antibodies. Even small amounts of contaminating IgG may create these problems, due to high concentrations of BSA in many protocols.


IgG-free BSA is supplied as a pure protein, freeze-dried from deionized water. Please inquire about availability of larger sizes.