Abstract: Constructed recombinant prokaryotic expression vector pET32a-VP73 was transformed into E.coli BL21, major antigenic epitope region of VP73 protein was induced stably and efficiently by IPTG, the result of SDS-PAGE showed, when final concentration of IPTG was 1.0 mmol/L, and pET32a-VP73 was induced 5 h, expression of major antigenic epitope region of VP73 protein was highest, the expressed protein was fusion protein, molecular weight was approximately 42 ku. The protein was identified as major antigenic epitope region of VP73 protein by SDS-PAGE and Western blotting. The purified major antigenic epitope region of VP73 protein was injected to New Zealand rabbits, serum was collected before and after injection. Antibody titer was determined by ELISA. Specificity of this protein was determined by ELISA whose primary antibody were ASF positive serum, rabbits serum before and after injection and positive serum of CSF, PRRS, pig pseudorabies. The result showed the titer of antiserum reached up to 1∶1024000, and gave rise to reactions with VP73 major antigenic region protein. The polyclonal antibody built the foundation for immunology research of VP73 and serological diagnosis of African swine fever.

Key words: African swine fever; VP73; prokaryotic expression; polyclonal antibody