Establishment and Application of the iELISA for Detection of Antibodies against ASFV
In order to establish an indirect enzyme-linked immunosorbent assay(iELISA)for detecting antibodies against African swine fever virus(ASFV),the gene expression engineering strain of recombinant ASFV P30 was induced and expressed,followed by purification and Western-blot detection of the recombinant proteins,then the iELISA method was established by taking the purified recombinant proteins as antigens,its specificity,sensitivity and repeatability were subsequently evaluated. Meanwhile,it was compared with the iELISA based on ASFV P30-2His6 protein(one His6 tag was fused respectively at N and C terminals)for veterinary clinical samples. The results showed that,by Western-blot detection,both the recombinant proteins of ASFV P30 and ASFV P30-2His6 could produce specific hybrid band with ASFV positive serum;the optimal reaction conditions of iELISA based on the recombinant ASFV P30 proteins were 20 μg/mL mass concentration of antigen protein coating,1:1 000 dilution of serum samples,1:40 000 dilution of goat anti-swine IgG conjugate,and 0.22 critical value of positive serum samples OD450. The established method was specific only to ASFV positive serum,1:3 200 diluted positive serum could still be detected,and the coefficients of variation(CV)of intra assay and inter assay were both less than 10%,which could eliminate any false positive reaction caused by His tag. Therefore,an effective tool was provided for detecting antibodies against ASFV by the established ASFV P30 iELISA in the study.