Abstract
A new method for the determination of serum uric acid was developed. In this method, uric acid is converted to allantoin, hydrogen peroxide and carbon dioxide by uricase (EC 1.7.3.3) and then allantoin is measured colorimetrically at 525 nm after condensation with diacetylmonoxime-thiosemicarbazide in 6N hydrochloric acid. In order to apply this method to serum, the coexisting urea is removed by urease (EC 3.5.1.5) treatment before the color reaction. Application of the method to patients'sera showed a good correlation with the results of a standard uricase-UV method ; the regression equation was y=0.954x+0.290 (mg/100 ml) and the correlation coefficient was γ=0.930. A characteristic feature of the new method is that it is not influenced by such commonly encountered interfering substances as ascorbic acid (160 mg/100 ml), glutathione (100 mg/100 ml), glucose (500 mg/100 ml) and bilirubin (10 mg/100 ml).
