Automated enzymatic micromethod for determination of uric acid in serum and urine with a centrifugal analyzer.

Uric acid is determined in serum and urine by an enzymatic method on a centrifugal analyzer. The sample (8 µl) is mixed with the enzyme uricase in a sodium borate buffer. The resulting decrease in absorbance at 292 nm is linearly proportional to the concentration of uric acid from 1 to 75 mg of uric acid per deciliter. Use of a centrifugal analyzer eliminates measurement of a separate serum blank. Recovery of uric acid added to serum and urine averaged 100% (range: 97-110%). Within-run precision (CV) on a serum pool for which the mean value was 5.96 mg/dl was 2.52%; day-to-day precision, measured on the same serum pool over a seven-day period, was 2.81% (mean: 6.05 mg/dl). Results obtained for serum with the uricase method on a centrifugal analyzer and with the uricase method on the Du Pont aca yielded a correlation coefficient of 0.99.