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Test ID ROXUR Oxalate, Random, Urine

Ordering Guidance

A timed 24-hour urine collection is the preferred specimen for measuring and interpreting this urinary analyte. Order OXU / Oxalate, 24 Hour, Urine.


Random collections normalized to urinary creatinine may be of some clinical use in patients who cannot collect a 24-hour specimen, typically small children. Therefore, this random test is offered for children under 16 years old.

Specimen Required

Patient Preparation: Avoid taking large doses (>2 g orally/24 hours) of vitamin C prior to specimen collection.

Supplies: Urine Tubes, 10 mL tube (T068)

Container/Tube: 10-mL plastic tube or a clean, plastic container with no metal cap

Specimen Volume: 7 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

3. Specimen pH should be between 4.5 and 8 and will stay in this range if kept refrigerated. Specimens with pH above 8 may indicate bacterial contamination, and testing will be cancelled. Do not attempt to adjust pH as it will adversely affect results.

Useful For

Monitoring therapy for kidney stones using random urine specimens


Identifying increased urinary oxalate as a risk factor for stone formation


Diagnosis of primary or secondary hyperoxaluria

Profile Information

Test ID Reporting Name Available Separately Always Performed
OXCO1 Oxalate, Random, U (mmol/L) No Yes
OXCO3 Oxalate, Random, U (mg/L) No Yes
CRETR Creatinine, Random, U No Yes
RAT11 Oxalate/Creatinine Ratio No Yes

Method Name

OXCO1: Enzymatic Using Oxalate Oxidase

CRETR: Enzymatic Colorimetric Assay

OXCO3, RAT11: Calculation

Reporting Name

Oxalate, Random, U

Specimen Type


Specimen Minimum Volume

6 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated 14 days

Reference Values

No established reference values

Day(s) Performed

Monday through Saturday

Report Available

3 to 5 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information



LOINC Code Information

Test ID Test Order Name Order LOINC Value
ROXUR Oxalate, Random, U 15086-2


Result ID Test Result Name Result LOINC Value
CRETR Creatinine, Random, U 2161-8
OXCO1 Oxalate, Random, U (mmol/L) 15086-2
OXCO3 Oxalate, Random, U (mg/L) 2700-3
RAT11 Oxalate/Creatinine Ratio 13483-3


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