Enhancement of coagglutination reactions of the Phadebact gonococcus test by ethylenediaminetetraacetate and ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetate.

Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity and enhancement of the coagglutination reaction of the Phadebact gonococcus test. These conditions included an alkaline pH (pH 8.3) and the presence of divalent cation chelators such as ethylenediaminetetraacetic acid or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. Heating cell suspensions at 90 degrees C for 15 min before assay by coagglutination produced a further increase in sensitivity and enhancement of the reaction. Gonococcal lipopolysaccharide was found to be an important antigen in these coagglutination reactions. The detection of lipopolysaccharide was markedly enhanced by the addition of chelating agents.