Diamine oxidase (DAO, EC1.4.3.6) widely exists in animals (intestinal mucosa, lung, liver, kidney, etc.),
plants and microorganisms. It can catalyze the oxidation of polyamines to aldehydes, and its activity is
closely related to the synthesis of nucleic acids and proteins. It can reflect the integrity and damage degree
of intestinal mechanical barrier.
DAO catalyzes the production of aldehydes and hydrogen peroxide from cadaverine, and it can catalyze
the oxidation of o-dianisidine by hydrogen peroxide to generate colored substances with adding excessive
horseradish peroxidase. This colored substance has a characteristic absorption at 500 nm. The activity of
DAO can be calculated by measuring the absorbance increase rate of this wavelength.
Reagents and Equipment Required but Not Provided：
Spectrophotometer/Microplate reader, low temperature centrifuge, 96-well flat-bottom plates/glass cuvette,
scales, distilled water.
