Purified bovine IgG may be used as a reference antigen, standard, blocking agent, or coating protein in a variety of immunoassays including ELISA, dot immunobinding, Western immunoblotting, immunodiffusion, and immunoelectrophoresis. Other applications include starting materials for the preparation of immunogens and solid phase immunoadsorbents. Bovine IgG was used as control in electrophoresis and in liquid chromatography.