Abstract: To obtain the anti-kappa casein monoclonal antibody and complete the identification of the antibody characteristics. The BALB/c mice were immunized with kappa casein using foot-pad immunization. Popliteal lymph node cells from the immunized mice were fused with SP2/0 myeloma cells in the presence of PEG. Three hybridoma strains (1C4, 3G3, 3E6) which secreted the antibody specific for kappa casein were obtained．The sub-class of the antibodies were IgG1. The ascites were purified by Protein G affinity layer absorption column. The antigenic epitope of 3G3 and 3E6 were different and it was close between 1C4 and 3E6.The titer of purified ascites(1C4) was 1.28×10⁶ and the affinity constant was 2.89×10⁸ mol/L. A anti-kappa casein monoclonal antibody with good affinity had been achieved，which provided foundations for the rapid detection of casein in bovine milk samples.

Key words: kappa casein; monoclonal antibody; characteristics identification