A protein immunoblot test for detection of bovine leukemia virus p24 antibody in cattle and experimentally infected sheep.

A protein immunoblot test for detecting antibody to the bovine leukemia virus p24 antigen is described. The test employs a crude antigen preparation derived from concentrated cell culture fluid, and an optimised biotin-streptavidin-peroxidase amplification system for immunodetection. The test is highly specific and is more sensitive than the gp51 agar gel immunodiffusion (AGID) test for detection of BLV antibody in cattle and experimentally infected sheep. In a selected set of 30 field sera from cattle which had given equivocal results in the gp51-AGID test, 21 were positive, 4 were negative, and 5 gave an uncertain result in the p24-immunoblot test.