Abstract: In order to highly express S protein of porcine epidemic diarrhea virus (PEDV) and prepare its specific polyclonal antibody，the main antigen region of S gene was amplified by PCR method，subcloned into pET30a(+) prokaryotic expression vector，transformed into BL21(DE3) expression bacteria，and induced by IPTG.The recombinant S protein was purified by affinity chromatography，its activity was detected by Western blotting，New Zealand White rabbits were immuned using the recombinant S protein to prepare polyclonal antibody，and detection of the antibody titer by indirect ELISA was conducted. After BamHⅠ/HindⅢ double enzyme digestion, we obtained pET30a-S recombinant plasmid，with induction of 1 mmol/L IPTG for 4 h，the recombinant S protein were expressed in inclusion body form，after purification and Western blotting，the protein showed good activity and specificity，antibody titer of polyclonal antibody against S protein was 1∶25600 detected by indirect ELISA. In this study PEDV S protein was successfully truncated expressed and its polyclonal antibody was also prepared，which layed a foundation for further development of rapid immunology detection kit of porcine epidemic diarrhea，and provided a condition for the study of structure and function of S protein and identification of the antigenic epitopes.

Key words:

porcine epidemic diarrhea virus; S protein; truncated expression; activity detection; polyclonal antibody