Evaluation of solid-phase enzyme-immunoassay procedure in immunity surveys and diagnosis of rubella

In the development of optimized micro-and macromethods for solid-phase rubella enzyme-immunoassay (EIA), the effect of various technical parameters was studied. Special emphasis was placed on elimination of defective polystyrene material, purity and quantity of immobilized antigen, use of reference sera in each microplate or macroprocedure, use of nonionic detergent in washing and diluent buffers, and use of a colourless enzyme substrate. A single serum dilution, analysed in duplicate, was sufficient provided the procedure was standardized. In quantitation of serum rubella antibodies, EIA gave values correlating well with those obtained with the single radial haemolysis test but not with low haemagglutination inhibition titres. The EIA procedure proved to be a useful and reliable serological tool in immunity surveys. When complemented by a rubella IgM test, EIA could also be used in diagnosis of recent rubella infections as a convenient primary serological test.