EN
The usefulness of an imfnunoperoxidase test in the detection of bovine leukemia virus (BLV) was demonstrated. Positive results of the PLA test were observed in cell cultures permanently infected with BLV (FLK, HKR and a 50% mixture of FLK and non-infected cells). A brown- -red colour of the antibody-antigen immunological complex of the cytoplasm of BLV infected cells confirms possitive results of the PLA test after anti-BLV serum addition. The nucleus of these cells was not stained. Unstained cells showing indistinct morphological structure confirm negative results of the PLA test. All FLK and HKR cells in the PLA test showed possitive reaction but in the case a 50% mixture of uninfected and infected cells, only 30% of the cell population were positive. The results of the PLA test with BLV infected cells were consistent with a syncytial test. In the case of cells transfected with the DNA of env gene of BLV the results of the PLA test positive, whereas a syncytial assay was negative.