Which uric acid measurement method is known to have negative bias from reducing agents?

The uricase coupled to the Trinder reaction is recognized for having a negative bias due to the influence of reducing agents. In this method, uric acid is oxidized to allantoin by uricase, and the resultant hydrogen peroxide is then reacted to produce a colorimetric change detected by a spectrophotometer. However, the presence of reducing agents can interfere with the reaction, leading to underestimation of uric acid levels. These agents reduce the hydrogen peroxide formed, which is critical in the color development process. This phenomenon results in a lower absorbance measurement than what would be expected, hence the negative bias.

This is an important consideration in clinical settings, as accurate uric acid measurement is crucial for diagnosing and managing conditions like gout and kidney diseases. Understanding this bias helps clinicians choose appropriate testing methods and interpret the results more effectively.