Enzyme-Linked Immunosorbent Assays Using the Recombinant gp51 and p24 of Bovine Leukemia Virus for Immunodetection of the Disease

Enzyme-linked immunosorbent assay (ELISA) is oftenused to test bovine leukemia virus (BLV) infection. However, commerciallyavailable kits test in South America detect only antibodies against the gp51protein. With the aim to improve the sensitivity of the test, we developed herea two-step indirect dual ELISA test that included both proteins p24 and gp51,expressed and produced in E. coli andbaculovirus expression system respectively. Two hundred ten BLV sera, stated asdouble positive or double negative by the combination of commercial agar gelimmunodiffusion (AGID) assay and a gp51-ELISA test, were tested with our inhouse dual rp24/rgp51 ELISA. Firstly, we checked the purified, optimized andstandardized proteins as antigen by the checkerboard technique, and set up ourin house ELISA test. The concordancecorrelation coefficient (CCC) and coefficient of variation (CV) intraplaterepeatability levels were within the values established by the internationalstandards. The statistical analysis demonstrated the value of sera correctlyranked highest (93.48%), and for 0.3 cutoff, the sensitivity was 95.65% and thespecificity 91.30%. In conclusion, the rp24/rgp51 ELISA developed andstandardized here demonstrated to have good analytical characteristics to beconsidered for screening of BLV.