[Enzymatic determination of uric acid in serum with the trinder reaction (author's transl)].

We describe a direct colorimetric method for the enzymatic assay of uric acid. 50 microliters serum aliquots are incubated for 30 min with a diluted hexacyanoferrate solution, to remove interference by non-specific reducing agents. Uric acid is then oxidized to allantoin in the presence of uricase (Aspergillus flavus), with the simultaneous production of hydrogen peroxide; this is measured by a modified Emerson-Trinder reaction, in which phenol has been replaced by sulphonated 2,4-dichlorophenol, a more sensitive chromogen. The method gives linear results up to 20 mg of uric acid/100 ml.