[Studies on the virus demonstration in enzootic bovine leukosis using the revertase test].

This exogenic test for the detection of enzyme activities (revertase) is helpful in differentiating between leucocytes of leukaemic cattle, on the one hand, and those of intact animals, on the other. The mechanism of such identification is based on differences in enzyme activity in the presence of poly rA/oligo dT and poly dA/oligo dT. The best results were obtained from short-time cultured leucocytes which gave ten times higher margins of incorporation by comparison between intact and preleucotic cattle. The morphological findings obtained by electron microscopy confirmed the results by other authors and enlarged them by determination, for the first time, of RNA filaments and protein rings.