The IDK® DAO ELISA is an enzyme immunoassay intended for the quantitative determination of diamine oxidase (DAO) in serum and dried blood spots.

For research use only. Not for use in diagnostic procedures.

For Laboratory Professional Use Only.

This is the RUO version of Immundiagnostik part number K 8500.

Developed by Immundiagnostik AG.

Test Principle of the IDK® DAO ELISA

The IDK® DAO ELISA is designed for the quantitative determination of DAO in serum and dried blood spots. The assay utilizes the sandwich technique with two polyclonal antibodies against recombinant DAO. Standards, controls, and prepared samples that are assayed for DAO are added into the wells of a microplate coated with polyclonal rabbit anti-DAO antibody.

During the first incubation step, DAO is bound by the immobilized primary antibody. Then a biotinylated polyclonal anti-DAO antibody is added to each microtiter well.

In the next step, the streptavidin peroxidase conjugate is added, and a “sandwich” of 1st antibody – DAO - biotinylated antibody – streptavidin peroxidase conjugate is formed. Tetramethylbenzidine (TMB) is used as peroxidase substrate.

Finally, an acidic stop solution is added to terminate the reaction. The color changes from blue to yellow. The intensity of the yellow color is directly proportional to the concentration of DAO.

A dose-response curve of the absorbance unit (optical density, OD at 450 nm) vs. concentration is generated, using the values obtained from the standard. The presence of DAO in the samples is determined directly from this curve.