ENZYME-BASED METHODS FOR IGM SEROLOGY - STANDARD INDIRECT ELISA VS ANTIBODY-CAPTURE ELISA

In a comparison of the performance (sensitivity and specificity) of standard indirect enzyme-linked immunosorbent assay (ELISA) and two antibody-capture ELISA methods, 50 serum specimens were tested for immunoglobulin M (IgM) to Toxoplasma gondii, and 54 serum specimens were tested for IgM to cytomegalovirus. The standard indirect ELISA was used with and without an adsorbent to eliminate interference from rheumatoid factor and competing IgG. Without the adsorbent, the standard indirect ELISA demonstrated low sensitivity compared with an indirect fluorescent antibody immunofluorescent assay reference method. With the adsorbent the standard indirect ELISA demonstrated equal specificity when compared with the antibody-capture method and significantly exceeded the capture method in sensitivity.