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Test Code LAB6226 Oxalate, 24 Hour, Urine

Additional Codes

OXU

Reporting Name

Oxalate, 24 Hr, U

Useful For

Monitoring therapy for kidney stones using 24-hour urine collections

 

Identifying increased urinary oxalate as a risk factor for stone formation

 

Diagnosis of primary or secondary hyperoxaluria

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Necessary Information


24-hour volume (in milliliters) is required.



Specimen Required


Patient Preparation: For 24 hours before, as well as during the collection process, patient should not take large doses (>2 g orally/24 hours) of vitamin C.

Supplies:

-Diazolidinyl Urea (Germall) 5.0 mL (T822)

-Sarstedt Aliquot Tube, 5mL (T914)

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

Specimen Volume: 4 mL

Collection Instructions:

1. Add 5 mL of diazolidinyl urea (Germall) as a preservative at start of collection or refrigerate specimen during and after collection.

2. Collect urine for 24 hours.

3. Mix container thoroughly and aliquot urine into plastic vial.

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

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  14 days
  Ambient  72 hours

Reference Values

0.11-0.46 mmol/24 h

9.7-40.5 mg/24 h

The reference value is for a 24-hour collection. Specimens collected for other than a 24-hour period are reported in unit of mmol/L for which reference values are not established.

 

Reference values have not been established for patients who are younger than 16 years.

Day(s) Performed

Monday through Saturday

CPT Code Information

83945

Testing Algorithm

For information see Hyperoxaluria Diagnostic Algorithm.

Report Available

3 to 5 days

Reject Due To

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

Method Name

Enzymatic

Urine Preservative Collection Options

Note: The addition of preservative must occur at the start of collection or application of temperature controls must occur during and after collection.

Ambient (No additive)

No

Refrigerate (No additive)

OK

Frozen (No additive)

No

50% Acetic Acid

No

Boric Acid

No

Diazolidinyl Urea

Preferred

6M Hydrochloric Acid

No

6M Nitric Acid

No

Sodium Carbonate

No

Thymol

No

Toluene

No

Forms

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