Test Details



Ordering Code


CPT-4 Code(s)

83945, 82570

Specimen Information

Patient Preparation

Patients should refrain from Vitamin C supplements during and for 48 hours prior to urine collection for oxalate.


24 hour urine. The bladder must be emptied at the time the collection is to begin, and this urine is discarded. Thereafter all urine must be collected until the end of the scheduled time. Collect urine with 25 mL of 6N HCl at start of collection to maintain pH between 1 and 3. Refrigerate urine during collection (critical). Mix the collection well before removing aliquot.

Specimen Preparation

Send 25.0 mL preserved urine in a screw capped plastic urine container. Record total volume on test requisition and specimen label.

Alternate Specimen

Alternate method of collection for 24 hour. Refrigerate urine during collection (critical) and add 25 mL of 6N HCl to the entire collection within 4 hours of completing. Mix the collection well before checking the pH. Ensure pH is between 1 - 3. Record total volume on test request and on container label. Send 25 mL aliquot refrigerated in a screw-capped plastic urine container.

Alternate method of collection for time urine sample: Requirements are the same as for 24 hour collection.

Minimum Volume

10.0 mL

Transport Temperature


Rejection Criteria

pH other than 1 - 3


Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 7 days



Reference Range

Males: 0 - 45 mg/24 hours
Females: 0 - 42 mg/24 hours

Urine Creatinine:
Males: 1.0 - 2.0 g/24 hours
Females: 0.8 - 1.8 g/24 hours
No reference ranges available for timed or random samples

Performing Laboratory

Warde Medical Laboratory

New York DOH Approval Status