Labeled avidin-biotin enzyme-linked immunosorbent assay (LAB-ELISA) for detection of Japanese encephalitis antibody in swine sera.

Labeled avidin-biotin (LAB) enzyme-linked immunosorbent assay (ELISA) was applied to detect Japanese encephalitis OE) antibody in swine sera. Purified laGAr-01 vaccine of lE, biotin labeled anti-swine Ig or IgM rabbit IgG conjugate and horseradish peroxidase (HRP) were employed in the assay. The f1 chain specific anti-IgM conjugate could detect only IgM antibody, but the anti-Ig conjugate could detect both IgM and IgG antibodibes to lE. When 2-2'-azino di-[3-ethylbenzthiazoline sulphonic acid] (ABTS) was used as a substrate to HRP, sensitivity of LAB-ELISA was essentially the same as that of ordinary ELISA, but approximately 20 times higher than that of hemagglutina-tion inhibition (HI) test. LAB-ELISA titers with ABTS were approximately 5 times higher than those with 5-amino salcylic acid (5-AS). However, non-specific reactions of sera were about 4 times lower in LAB-ELISA than in ordinary ELISA.