A simplified procedure for the routine determination of uric acid.

DESPITE THE NUMEROUS procedures available for the determination of uric acid, their clinical use remains subject to considerable error. A simple precise method for routine clinical use is desirable since determination of the level of serum uric acid is an important criterion for the diagnosis of gout. Excellent critical reviews of the available methods have been published (1, 2, 3). The currently available procedures with the highest degree of specificity and precision depend on the enzymatic destruction of uric acid by uricase. These involve, however, a laborious technic-the use of a highly purified and uniform supply of uricase, not always readily available-and they suffer from the errors inherent in all spectrophotometric determinations. The only available procedure for the direct reading of the uric acid content of a solution is ultraviolet spectography. This, however, is impractical for routine analyses and involves preliminary purification of the test material with its inherent sources of error. Methods for determining uric acid which depend on its enzymatic destruction also involve many sources of error that can be avoided only by complicated procedures. The most commonly used methods depend on the colorimetric determination of uric acid. This is nonspecific and hence is subject to erroneously high values due to the presence of chromogens other than uric acid. Other sources of error in uric acid analysis are the ease with which this substance is adsorbed when serum is deproteinated, and the presence in serum of