Abstract: An indirect ELISA was established for the rapid detection of specific Japanese encephalitis virus (JEV) antibodies in swine using a recombinant E protein as an antigen. The recombinant E protein was expressed from recombinant plasmid pET28a-E in Escherichia coli. The various factors affected the experiments were optimized. This assay was optimized using 2 μg/mL E protein as coat antigen, the optimal coating condition of JEV for ELISA was incubated at 37 ℃ for 2 hours, 1∶160 dilution of testing serum and 1∶5000 dilution of HRP-labeled goat anti-swine IgG, the best blocking buffer was BAS with 1% consent ration. The critical value of positive and negative of ELISA was D492 nm=0.254, this method is not with the serums of CSFV, PRRSV, PCV2, PRV reaction, D492 nm<0.254, explain its specificity. Test against 150 serum samples from Jilin province by this assay detected 43.33% positive, which showed 90.77% agreement with ELISA kit test. Therefore, this study indicated that an indirect ELISA method for specifically detection JEV in serum was successfully established.

Key words: Japanese encephalitis virus; recombinant E protein; indirect ELISA