Enzyme-linked immunosorbent assay for determination of rubella IgG antibodies.

A rubella virus antigen suited for enzyme-linked immunosorbent assay (ELISA) was grown in cultures of BHK/21/13 cells and purified and concentrated by membrane and ultrafiltration. This antigen was used in a semi-automated ELISA for determination of rubella IgG antibodies. The ELISA and the haemagglutination-inhibition (HI) test were compared in a study of 825 human sera. A close correlation was found between the results obtained by the two methods. Antibodies were, however, detected with ELISA in approximately 15% of the sera found negative in the HI test. The presence of antibodies was confirmed by the results of HI tests of the serum fractions of 19 sera separated by rate zonal ultracentrifugation. The EISA procedure employed in the present study was highly sensitive and allowed a precise quantitation of the antibodies by examination of one single serum dilution. ELISA was less time-consuming than the HI test and suited for routine laboratory use.