Detection of cytotoxic antibodies in the serum of cattle with leukemia

: In a set of 55 serum samples obtained from the herd of bulls heavily infested with bovine leukosis we tested the applicability of cytotoxic test for the diagnostics of bovine leukosis we tested the applicability of cytotoxic test for the diagnostics of bovine leukosis and compared the results with immunodiffusion test in agar. The two tests show approximately the same sensitivity because in each examined sample the results of cytotoxic test corresponded at least in two out of three serum dilutions (1:2, 1:5 and 1:7) to the immunodiffusion test. It has been demonstrated that as regards the cytotoxic test, the final serum dilution of 1:5 was satisfying. At the same time it has been checked that the bovine foetal serum, required for the growth of cell cultures, could be replaced by the bovine serum treated with the 40% solution of polyethylene glycol (PEG) 6000 without any influencing the results of cytotoxic test.