Isolation and characterization of monoclonal antibodies monospecific for bovine alpha-casein and beta-casein.

Two monoclonal antibodies monospecific for bovine alpha s1-casein, which recognize three genetic variants of alpha s1-casein, have been isolated and their binding properties characterized. Antibodies 57-115 and 57-310 recognize different antigenic determinants on the alpha s1 protein with affinity constants of 1.63 x 10(11) and 2.13 x 10(11) M-1, respectively. Five monoclonal antibodies, 58-409, 58-416, 58-488, 58-504, and 58-557, monospecific for bovine beta-casein with affinity constants greater than 10(9) M-1, which recognize a similar epitope(s) also were isolated. All seven antibodies are of isotype IgG1 and recognize both the denatured and undenatured forms of their antigen, making them suitable for qualitative and quantitative radioimmunoassay.