title: Use of 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone chromogenic system in direct enzymic assay of uric acid in serum and urine.
abstract: A new direct colorimetric procedure for uric acid assay in serum or urine is described, utilizing a 3,5-dichloro-2-hydroxybenzene sulfonic acid/4-aminophenazone chromogenic system in the presence of horseradish peroxidase and uricase from Aspergillus flavus. This chromogen system has a high absorptivity, affording useful results with sample/reagent volume ratios as low as 0.025. The procedure is applicable to serum, plasma, or diluted urine. A single working reagent is used; the reaction is complete in less than 15 min at room temperature. The red dye formed is measured at 520 nm; a blank sample measurement is not needed. The standard curve for the method is linear for uric acid concentrations up to 1500 mumol/L. Average analytical recovery of uric acid in human sera and urine exceeded 99%; within-run and between-run precision studies showed CV's of less than or equal to 1.2 and less than or equal to 2.2%, respectively. The new procedure correlated well with the uricase/catalase and uricase/ultraviolet methods. The method is suitable for automation.
mesh_terms: D000632:Aminopyrine; D001205:Ascorbic Acid / Q000032:analysis; D001557:Benzenesulfonates; D001663:Bilirubin / Q000032:analysis; D003124:Colorimetry / Q000379:methods*; D004347:Drug Interactions; D006801:Humans; D007202:Indicators and Reagents; D010544:Peroxidases / Q000032:analysis; D014503:Urate Oxidase / Q000032:analysis; D014527:Uric Acid / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D001557:Benzenesulfonates; D007202:Indicators and Reagents; D000632:Aminopyrine; C024018:3,5-dichloro-2-hydroxybenzenesulfonic acid; D014527:Uric Acid; D010544:Peroxidases; D014503:Urate Oxidase; D001205:Ascorbic Acid; D001663:Bilirubin