A sandwich enzyme immunoassay for wheat gliadin.

A sandwich double antibody solid-phase enzyme immunoassay (EIA) that can detect and quantitate gliadin is described. Quantitative analysis could be carried out in the range of 5-400 ng/ml and the assay was more sensitive than inhibition EIA. Gliadin possessed weak cross-reactivity with oats, maize and rice prolamines. In the presence of anti-gliadin antibody (serum from a patient with active coeliac disease) gliadin could not be detected, but the sensitivity of the assay was restored by heat treatment of the serum. This EIA can therefore be employed to assess the gliadin content of biological fluids where specific antibody may coexist.