New enzymatic method for serum uric acid at 500 nm

Area of Science:

• Clinical Chemistry
• Biochemical Assays

Background:

• Accurate quantification of serum uric acid is crucial for diagnosing conditions like gout and kidney disease.
• Existing methods may have limitations in terms of speed, sensitivity, or susceptibility to interference.

Purpose of the Study:

• To develop and validate a manual, mechanization-friendly method for serum uric acid quantitation.
• To establish the sensitivity, linearity, and interference profile of the proposed assay.

Main Methods:

• A colorimetric assay utilizing uricase, peroxidase, p-hydroxybenzoate, and 4-aminoantipyrine to detect hydrogen peroxide produced by uric acid.
• A single absorbance measurement after sample addition obviates the need for a separate sample blank.
• Assay performed at 500 nm with a reaction time of 5 minutes.

Main Results:

• The method demonstrates high sensitivity (0.001 deltaA/mg per liter) and linear response up to 120 mg/liter.
• Minimal interference from common serum components, though bilirubin requires specific correction.
• Excellent correlation (r = 0.979) with the established 293 nm reference method.

Conclusions:

• The described manual method provides a sensitive, rapid, and reliable means for serum uric acid measurement.
• Its suitability for mechanization and good correlation with reference methods make it valuable for clinical laboratories.
• The assay offers a practical alternative for routine uric acid quantitation.