Comparison of four methods for measuring uric acid: copper-chelate, phosphotungstate, manual uricase, and automated kinetic uricase.

Glutathione,ascorbicacidand many commonly used antibiotics falsely elevate uric acid concentrations when measured with the Du Pont “aca,” in which the copper-chelate method is used. L-Dopa interferes with both the copper-chelate method and the Technicon “SMA 12/60” phosphotungstate method. A new kinetic uricase method has been developed for use on the Du Pont aca. This kinetic uricase method has a coefficient of variation of 2.40% and gives values that are essentially identical to those obtained by a manual end-point uricase method.