10 mL (5 mL min.) aliquot of 24 hour urine. Do not use preservatives. Ship refrigerated or frozen. Record 24 hour volume on test request form and urine container.
This assay is useful for the assessment and management of patients with kidney stones, particularly uric acid stones. Urinary uric acid excretion is elevated in a significant proportion of patients with uric acid stones, due to uric acid overproduction as in Leukemia and Polycythemia and after intake of food rich in nucleoproteins.