Abstract: In order to determine the level of antibody against PEDV in swine serum.The PEDV recombinant N protein was expressed by E.coli and purified through native conditions purification method.Based on purified recombinant N protein, an indirect ELISA for detection of anti-PEDV antibodies was developed and its optimal reaction conditions were determined:antigen working concentration was 0.5 μg/mL, it was coated at 37 ℃ for 2 h and 4 ℃ overnight, serum samples dilution was 1:100, incubated at 37 ℃ for 45 min.HRP-labeled rabbit anti-pig IgG was diluted at 1:10 000, incubated at 37 ℃ for 60 min, the substrate for showing color was incubated at 37 ℃ for 15 min. It was judged to be positive when the OD was greater than the cut off OD_450nm of 0.30, as negative when OD_450nm was smaller than 0.27, and as suspicious between 0.27 and 0.30.The established ELISA assay was confirmed to be good in specificity, sensitivity and repeatability by repeatability and cross test.A total of 184 clinical serum samples obtained from pig farms in Zhejiang Province were detected by using the established ELISA and the positive rate was 68.5%.

Key words: Porcine epidemic diarrhea, Recombinant N protein, ELISA

CLC Number: 

• S828