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HelpOrder Code 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, USpecimen Type
UrineSpecimen Minimum Volume
6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days | ||
| Ambient | 72 hours |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
No established reference values
Method Description
The assay utilizes oxalate oxidase, which oxidizes oxalate to carbon dioxide and peroxide. In the presence of peroxidase, the peroxide oxidatively couples 3-methyl-2-benzothiazolinone and 3-dimethylaminobenzoic acid to form indamine dye, which is measured spectrophotometrically at 600 nm.(Kasidas GP, Rose GA. Continuous-flow assay for urinary oxalate using immobilized oxalate oxidase. Ann Clin Biochem, 1985;22:412-419; package insert: Oxalate kit. Trinity Biotech; V 11/2017)
Day(s) Performed
Monday through Saturday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
83945
82570
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.