An infectivity assay for the bovine leukemia virus based on the induction of the major internal virion antigen in susceptible cell cultures.

This report described the development of a 7-day infectivity assay for the bovine leukemia virus (BLV) which is based on the induction of the major internal virion antigen (p25) in susceptible indicator monolayer cell cultures. In this assay the antigen is detected in the indicator cells by the immunoperoxidase antibody technique using a monospecific anti-BLV serum. The immunoperoxidase infectivity assay (IPIA) is specific, quantitative, reproducible and more sensitive than the previously developed syncytia induction assay. The IPIA can be applied for the detection of BLV-infected cells and provides a reliable method for the direct diagnosis of BLV infection in cattle.