Diagnosis of pre- and postnatal rubella by demonstration of specific IgM-class antibodies by a microplate immunofluorescence test.

An indirect immunofluorescence technique employing rubella virus infected SIRC-cells grown in flat-bottomed plastic plates is described for the detection of specific IgM-class rubella antibodies in serum fractions obtained by sucrose density ultracentrifugation. The results were read by means of a fluorescence microscope with an incident light illuminator. A total of 176 serum specimens from five groups of patients were used for determination of the specificity and sensitivity of the test. The technique proved to be less time consuming and in addition to be more sensitive than the hemagglutination-inhibition method for the detection of rubella IgM-class antibodies.