[Use of protective anthrax antigen in agglutination reactions].

The latex- and hemagglutination tests were applied to determination of the titres of anthrax antibodies in the sera of 982 immunized sheep. Monodispersive standard colur latex of polymethylmetacrylate and protective anthrax antigen was used in these tests. On the basis of the results of titration of control sera titres of anthrax antibodies over 1:16 in the latex- and hemagglutination tests were accepted as positive. There was revealed no difference between the sera of the immunized animals reacting positively in both tests (d = 1.87 less than delta = 2.94 at P = 0.95). The difference between the positive titres determined in the latex-agglutination (55.78%) and hemagglutination (44.41%) tests was significant (d = 11.37 less than delta = 4.39 at P = 0.95). Consequently, both tests could be used for the purpose of determination of anthrax antibody titres, but the latex-agglutination test was more sensitive of the two.