DGP Ab IgA ELISA

INTENDED PURPOSE

DGP Ab IgA is an ELISA test system for the quantitative detection of antibodies (IgA) against deamidated gliadin protein epitopes (DGP) in human serum or plasma. This product is intended for professional in vitro diagnostic use only.

Determination of anti-DGP antibodies is an aid in the diagnosis of coeliac disease. The interaction between dietary gliadin peptides and the intestinal enzyme tissue transglutaminase (tTG) causes the formation of novel antigenic epitopes, the tTG-generated deamidated gliadin peptides (DGP), and anti- DGP antibodies are specific serological markers for the disease. Laboratory tests for disease specific autoantibodies contribute to diagnostics, together with clinical observations and histology of the small intestinal mucosa.

PRINCIPLE OF THE TEST

Deamidated gliadin proteins are bound to microwells. The determination is based on an indirect enzyme linked immune reaction with the following steps: Specific antibodies in the patient sample bind to the antigen coated on the surface of the reaction wells. After incubation, a washing step removes unbound and unspecifically bound serum or plasma components. Subsequently added enzyme conjugate binds to the immobilised antibody-antigen complexes. After incubation, a second washing step removes unbound enzyme conjugate. After addition of substrate solution the bound enzyme conjugate hydrolyses the substrate forming a blue coloured product. Addition of an acid stopps the reaction generating a yellow end-product. The intensity of the yellow color correlates with the concentration of the antibody-antigen-complex and can be measured photometrically at 450 nm.