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Test ID URCU Uric Acid, 24 Hour, Urine

Reporting Name

Uric Acid, 24 HR, U

Useful For

Assessment and management of patients with kidney stones, particularly uric acid stones

Specimen Type


Ordering Guidance

X-ray dyes and contrast media will affect test results.

-If a kidney X-ray with dye or computerized tomography (CT) scan with contrast has been performed, patient should wait a minimum of 1 day before starting collection.

-If a cholangiography (bile duct X-ray) has performed, patient should wait 7 days before starting collection.

-Urine must be collected before tablets have been taken for gallbladder X-ray, otherwise patient should wait 7 days before starting collection.

Necessary Information

24-Hour volume is required.

Specimen Required

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Collection Container/Tube: 24-Hour graduated urine container with no metal cap or glued insert

Submission Container/Tube: Plastic, 5 mL tube or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 5 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  30 days
  Ambient  7 days

Reference Values

Males ≥18 years old: 200-1,000 mg/24 hours

Females ≥18 years old: 250-750 mg/24 hours


Reference values have not been established for patients who are less than 18 years of age.

The reference value is for a 24-hour collection.

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
URCU Uric Acid, 24 HR, U 3087-4


Result ID Test Result Name Result LOINC Value
UACID Uric Acid, 24 HR, U 3087-4
TM29 Collection Duration 13362-9
VL27 Urine Volume 3167-4

Clinical Information

Uric acid is the end-product of purine metabolism. It is freely filtered by the glomeruli and most is reabsorbed by the tubules. There is also active tubular secretion.


Increased levels of uric acid in the urine usually accompany increased plasma uric acid levels unless there is a decreased excretion of uric acid by the kidneys. Urine uric acid levels reflect the amount of dietary purines and endogenous nucleic acid breakdown.


Urinary uric acid excretion is elevated in a significant proportion of patients with uric acid stones.


Uric acid excretion can be either decreased or increased in response to a variety of pharmacologic agents.


Urine uric acid levels are elevated in states of uric acid overproduction such as in leukemia and polycythemia and after intake of food rich in nucleoproteins.


High levels of bilirubin and ascorbic acid may interfere with measurement.

Clinical Reference

1. Lamb EJ, Jones GRD: Kidney function tests. Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:500-503

2. Newman DJ, Price CP: Renal function and nitrogen metabolites. In: Tietz NW, ed. Textbook of Clinical Chemistry. WB Saunders Company; 1999:1245-1250

Method Description

Uric acid is oxidized by the specific enzyme uricase to form allantoin and peroxide. Peroxide reacts in the presence of peroxidase and a color reagent to form a red color, the intensity of which is proportional to the uric acid concentration.(Package insert: Roche Uric Acid Plus. Roche Diagnostics; V13.0 05/2019)

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name


Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.







50% Acetic Acid


Boric Acid


Diazolidinyl Urea


6M Hydrochloric Acid


6M Nitric Acid


Sodium Carbonate








If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 to 3 days