Description:
<jats:title>SUMMARY</jats:title><jats:p>A radioimmunoassay (RIA) has been developed to measure antibodies against<jats:italic>Brucella abortus</jats:italic>in bovine serum and can be used in the diagnosis of bovine brucellosis. The RIA measures the amount of specific antibody of the IgG<jats:sup>1</jats:sup>and IgG<jats:sup>2</jats:sup>subclasses but is insensitive to 1gM, a characteristic which may make it more suitable than the complement fixation test (OFT) or the serum agglutination test for distinguishing infected animals from those which have been vaccinated with<jats:italic>Br. abortus</jats:italic>strain 19. The RIA is not subject to prozoning or ambiguous reactions, both of which interfere with the interpretation of the CFT.</jats:p>