[Detection of the provirus of the bovine leukemia virus in bovine peripheral blood leukocytes by means of DNA hybridization].

The method allowing the detection of BLV proviral DNA in the peripheral blood leukocytes of cattle is reported. Cell DNA from leukocytes used without preliminary cultivation was dot-hydridized with 32P-labeled plasmid that included a fragment of BLV proviral DNA. In parallel, sera from the cattle under study were tested by immunodiffusion assay (ID). The results indicate that dot-hybridization assay is more sensitive as a diagnostic test than ID because it detects BLV infection in apparently normal cattle which was seronegative by ID.