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HelpTest Code LAB3362 Oxalate, Plasma
Additional Codes
Oxalate
Specimen Required
Any client who has never collected a specimen for this test should call 800-533-1710 or 507-266-5700 and ask for the Clinical Specialty Laboratory for more detailed instructions.
Patient Preparation:
1. Fasting (for a minimum of 12 hours)
2. Patient should avoid taking vitamin C supplements for 24 hours prior to collection.
Specimen Type: Acidified plasma
Collection Container/Tube: Green top (sodium heparin)
Submission Container/Tube: Plastic vial
Specimen Volume: 5 mL
Collection Instructions:
1. Place specimen on wet ice immediately.
2. Centrifuge for 10 minutes at 3500 rpm within 1 hour of collection. Use of a 4° C refrigerated centrifuge is optimal but not required.
3. Aliquot plasma into a plastic vial.
4. Adjust the pH of the plasma specimen to a pH of 2.3-2.7 with approximately 10 mcL concentrated (12M) hydrochloric acid (or 20 mcL of 6M HCl) per 1 mL plasma.
Additional Information: Nonacidified specimens can be accepted if the heparinized plasma is properly frozen. A disclaimer will be added in nonacidified plasma, "Sample was received nonacidified and frozen. In nonacidified samples oxalate values may increase spontaneously." Although there can be a small absolute increase of plasma oxalate in nonacidified specimens, this will not change the clinical interpretation.
Useful For
Assessing the body pool size of oxalate in patients with enzyme deficiencies, such as primary hyperoxaluria (PH), or patients with enteric hyperoxaluria
Aiding in the diagnosis of PH in a patient with chronic kidney disease of indeterminate cause when urinary oxalate is not available
Monitoring patients with renal failure and primary or enteric hyperoxaluria in order to be sure they are receiving enough dialysis
Aiding in maintaining plasma oxalate levels below supersaturation (25-30 mcmol/L)
Special Instructions
Method Name
Enzymatic
SCH Clinical System Name: Oxalate
Reporting Name
Oxalate, PlasmaSCH Clinical System Name: Oxalate
Specimen Type
Plasma Na HeparinSpecimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma Na Heparin | Frozen | 30 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
≤2.0 mcmol/L
Reference values have not been established for patients younger than 18 years of age or older than 87 years of age.
Method Description
This is an enzymatic method based on the reduction of oxalate by oxalate oxidase. The reaction releases hydrogen peroxide, which in the presence of peroxidase reacts with a dye to give a colored end point that is measured using a BioTek EPOCH plate spectrophotometer at 590 nm.(Package insert: Oxalate Kit. Trinity Biotech; V. 07/2016)
Day(s) Performed
Monday through Friday
Report Available
3 to 7 daysPerforming 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
83945
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| POXA1 | Oxalate, Plasma | 15085-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| POXA1 | Oxalate, Plasma | 15085-4 |
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.