Brucella abortus which causes Brucellosis or undulant fever is contracted by contact with infected animals or by the ingestion of their by-products. Brucella abortus is a gram-negative bacterium found in the cattle population. On exposure the body responds by producing specific antibodies to the Brucella species whose titres rise slowly at early stages and then increases.

The Biorex Diagnostics Brucella agglutination test is a serological test for Brucellosis. Specific antibodies to the Brucella species are detectable a few weeks after exposure. Specific antibodies to Brucella antigens if present in serum will react with the antigen suspension to produce an agglutination reaction. No agglutination indicates the absence of the specific antigens.