Detection of avian oncovirus group-specific antigens by the enzyme-linked immunosorbent assay.

A three-step sandwich enzyme-linked immunosorbent assay was developed for the detection of avian oncovirus group-specific (gs) antigens. The assay procedure was to coat the wells of microtitre plates with hamster anti-gs IgG, react with crude or purified antigen and finally with hamster anti-gs IgG linked to horseradish peroxidase. The sensitivity was 8 picograms (pg) of input avian myeloblastosis virus (AMV) protein, with negligible background. As the ELISA takes less than 2 h to perform, large-scale screening for infected birds is feasible. A blocking assay was also developed for detecting anti-gs antibodies by adding unlabelled antiserrum after the antigen step.