Improved sensitivity and specificity of sandwich, competitive and capture enzyme-linked immunosorbent assays for allergen-specific antibodies.

Indirect ELISA is widely used to detect specific antibodies but can suffer from high non-specific binding-particularly of IgG. The use of affinity-purified rabbit antibody-coated microtitre plates to bind antigen greatly increases sensitivity without a significant increase in non-specific binding of IgG. Capture, competitive and sandwich assay procedures gave comparable results for IgG antibodies; but only the sandwich assay was suitable for detection of IgE antibodies.