An evaluation of ELISA kits for rubella IgG- and IgM-antibodies

Two ELISA kits for rubella IgG- and IgM-antibodies, respectively, were compared with a haemagglutination inhibition (HAI) test (after ultracentrifugation of the sample if IgM was to be detected). When screening 535 samples from pregnant women, 99.6% agreement was found between the IgG-ELISA and HAI; one true IgM-positive was encountered in this group with the IgM-ELISA. An agreement of 95.5% was found between the IgM-ELISA and HAI after ultracentrifugation. In at least some of the discrepant samples the IgM-ELISA may be assumed to have given the correct answer.