| cross-reactions of normal bovine serums to foot-and-mouth disease virus in plaque-reduction neutralization and radial immunodiffusion. | serums from 150 cattle with no known exposure to foot-and-mouth disease (fmd) virus were tested by both the plaque-reduction neutralization (prn) technique and the radial immunodiffusion (rid) technique to evaluate the significance and the extent of cross-reactions in these tests. serums from 30 cattle from each of 5 locations were tested against representative viruses of each of the 7 types of fmd virus. high levels of cross-reactions with both the rid and prn techniques were found in serums of ... | 1975 | 167625 |