Abstract: The expressed and purified Clostridium perfringens β2 toxin recombinant protein was used as the coating antigen, and four monoclonal antibodies (McAbs) with ELISA detection function from 21 strains of Clostridium perfringens β2 toxin monoclonal antibodies were selected. Then using the recombinant β2 toxin protein as the coating antigen, an indirect ELISA method for the detection of Clostridium perfringens β2 toxin antibody was established by optimizing the reaction conditions. And it was finally determined that the optimal coating concentration of the antigen was 0.5 μg/mL, the dilution ratio of the antibody was 1∶210（0.029 μg/μL）, the dilution ratio of the secondary antibody was 1∶2 000, and the blocking condition was 5%. The skimmed milk was blocked at 37 ℃ for two hours. The test results showed that the method had good specificity, sensitivity and stability. Using the established indirect ELISA detection method, 201 normal bovine sera, two positive sera, and one negative serum were tested by ELISA. Both the negative coincidence rate and the positive coincidence rate were 100%. The ELISA detection method established in this study can be used to detect the level of Clostridium perfringens β2 toxin antibody in animal serum, which provides an effective detection method for understanding animal cPB2 toxin infection and antibody level, and has broad application prospect in clinical seroepide miological investigations and vaccine immunity evaluation.

Key words: Clostridium perfringens β2 toxinrecombinant protein, monoclonal antibody, indirect ELISA, antibody detection