Standardization of the double-antibody method for IgE determination: use of different monoclonal IgE as tracer, immunogen or standard.
We wanted to determine whether the competitive radioimmunoassay for IgE is influenced by various combinations of three monoclonal IgE (IgEND, IgEPS, IgESHA) used as tracer or standard, and anti-IgEND and anti-IGEPS as first antibody. When the immunogen for the first antibody was identical with the monoclonal tracer or standard IgE, the latter two bound preferentially to the first antibody. These unusual assays led to inhibition curves that ran in parallel to those produced by usual assays, i.e. assays in which the tracer and the immunogen were different monoclonal IgE and the standard was a polyclonal IgE. When serum samples were analyzed for their IgE content, the unusual assay produced values that were linearly related to those produced by a usual or another, unusual, assay. However, the values of IgE produced by a usual assay were, in general, significantly different from those obtained by unusual assays. We conclude that as suspected, but never demonstrated before, the competitive assay for IgE requires the use of two different monoclonal IgE as tracer and immunogen; application of unusual assays requires their prior calibration against a usual assay.
D000818:Animals; D000911:Antibodies, Monoclonal; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis*; D011786:Quality Control; D011863:Radioimmunoassay; D012015:Reference Standards
D000911:Antibodies, Monoclonal; D007073:Immunoglobulin E