Use of the double immuno gel diffusion test and the enzyme-linked immunosorbent assay to distinguish false from true...

A gel diffusion test with sonicated Brucella ovis antigen and an enzyme-linked immunosorbent assay based on heat-extracted antigen were used to distinguish false from true reactions in a complement fixation test based on heat-extracted antigen. Of 142 complement fixing reactors (occurring in supposedly Brucella ovis-free, accredited flocks), the gel diffusion test correctly identified the status of 139 animals as compared to 128 with the enzyme-linked immunosorbent assay. A combination of the two methods resulted in a correct identification of 141 animals. The procedures provide an easy, cheap and quick way to determine the true status of reactors that show up during routine use of the complement fixation test in Brucella ovis re-accreditation procedures.