Uric acid is oxidised by the action of uricase to allantoin and hydrogen peroxide. In the presence of peroxidase (POD) the mixture of dichlorophenol sulphonate (DCBS) and 4-aminoantipyrine (4-AA) are condensed by the action of hydrogen peroxide, forming a coloured quinonaimine proportional to the concentration of uric acid in the sample.
