Bordetella pertussis IgA ELISA

Enzyme immunoassay for the qualitative determination of IgA class antibodies against Bordetella pertussis. Bordetella species are non-spore-forming encapsulated bipolar, coccoid (pale-staining) Gram-negative bacilli (about 0.3-0.5 μm thick and 1 μm long).

The qualitative immunoenzymatic determination of IgA-class antibodies against Bordetella pertussis is based on the ELISA (Enzyme-linked Immunoorbent Assay) technique. Microtiter strip wells are precoated with Bordetella pertussis/toxin antigens to bind corresponding antibodies
of the specimen. After washing the wells to remove all unbound sample material horseradish peroxidase (HRP) labelled anti-human IgA conjugate is added. This conjugate binds to the captured Bordetella pertussis/toxin specific antibodies. The immune complex formed by the bound conjugate is visualized by adding tetramethylbenzidine (TMB) substrate which gives a blue reaction product. The intensity of this product is proportional to the amount of Bordetella pertussis/toxin specific IgA antibodies in the specimen. Sulfuric acid is added to stop the reaction. This produces a yellow endpoint colour. Absorbance at 450nm is read using an ELISA microwell plate reader.