Detection of Q fever antibodies in whey by the anti-globulin sensitization test and other techniques

1. Samples of whey from individual cows and herds infected with R. burneti and from uninfected cows and herds have been tested for R. burneti antibodies. 2. The haemolytic complement-fixation test, the conglutinating complement-absorption test, the direct agglutination test and the anti-globulin sensitization test were compared for sensitivity in detecting whey antibody. 3. The direct agglutination test was generally more sensitive than either of the complement-fixation tests, particularly when it was enhanced by centrifugation of the sensitized rickettsiae. The anti-globulin sensitization test, however, gave the highest titres andit appeared to be specific. 4. The practical application of these techniques and certain theoretical considerations are discussed.