Haemolysis in gel test for detecting bovine antibodies to Brucella abortus lipopolysaccharide.

Optimal reagent parameters for a haemolysis in gel test for detection of bovine anti-Brucella abortus antibody were established. Using an alkali-treated crude lipopolysaccharide antigen attached to J-negative bovine erythrocytes, 0.125 mg of antigen, 0.1 ml of erythrocytes and 0.4 ml of guinea pig complement were required to perform 15 tests with appropriate serum controls. The haemolysis in gel test and an IgM radioimmunoassay (RIA) procedure were compared for their ability to detect the onset of increased serum antibody levels and antibody levels in sera diluted to extinction. While the RIA was more sensitive in amount of antibody detected, the haemolysis in gel test was equally able to detect initiation of antibody synthesis.