Fig. 1.

Comparison of the IgG and IgA dose-response curves for single- (monoplex) and dual-label DELFIAs. Purified IgG or IgA were serially 2-fold diluted (10.0 to 0.0049 μg/ml) and were detected using either monoclonal mouse anti-human IgG-labeled Sm³⁺ (IgG-Sm) or anti-human IgA-labeled Eu³⁺ (IgA-Eu). For the duplex assay, the Sm³⁺ and Eu³⁺ monoclonal conjugates were added simultaneously to the same well at the same concentration as for the monoplex assay. The maximum specific binding (B_max) and equilibrium binding constants were not significantly different when comparing the monoplex and duplex assays for either IgG or IgA.