A double-antibody radioimmunoassay for specific IgE to ragweed antigen E

A double-antibody radioimmunoassay has been developed for quantitating IgE-a-AgE in serum. The patient's IgE is complexed by rabbit anti-human IgE, which is then precipitated with GARG. Radiolabeled AgE is then added to the washed precipitate and is specifically bound by IgE-a-AgE. This assay is highly reproducible, and unlike specific IgE assays based on the RAST concept, it cannot be inhibited by specific antibody of other immunoglobulin classes (blocking antibody). In addition, the double-antibody method does not require the use of myeloma IgE, and its results correlate well with those of a previously developed polystyrene tube method.