Dual-labeled time-resolved immunofluorometric assay for the determination of IgM antibodies to rubella virus and cytomegalovirus in human serum

Objectives: This study established a novel time-resolved fluorescence immunoassay (TRFIA) that allows the simultaneous determination of rubella virus (RV) IgM and cytomegalovirus (CMV) IgM in human serum.

Design and methods: Lanthanum elements labeled antibody and streptavidin-biotin system were used in the "capture sandwich" format simultaneously.

Results: The working range of TRFIA for RV IgM was 2-80 AU/mL and for CMV IgM was 5-400 AU/mL. Intra- and inter-assay coefficient of variation (CV) for RV IgM and CMV IgM were both less than 10% and recoveries were from 90% to 110%. No significant statistical difference in sensitivity or specificity was observed between dual-TRFIA and commercial chemiluminescent immunoassays (CLIA) in serum samples.

Conclusion: The novel dual-TRFIA for RV IgM and CMV IgM detection might have valuable clinical application, with satisfactory sensitivity, specificity and accuracy.