Oxalate, Serum/Plasma

Test Code

5390

CPT Codes
83945

Preferred Specimen

2 mL serum collected in a red-top tube (no-gel)

Patient Preparation
It is recommended that patients refrain from taking excessive amounts of vitamin C or vitamin C rich food for at least 48 hours prior to collection.

Minimum Volume

0.7 mL

Other Acceptable Specimens

Plasma collected in: Sodium heparin (green-top) tube

Instructions

Promptly centrifuge with refrigeration and separate serum or plasma into chilled plastic screw-cap vial using approved guidelines.

Note: Ascorbic acid at very high concentration (exceeding 51 mcmol/mL plasma) can interfere.

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 14 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Received room temperature • Sodium fluoride/potassium oxalate (gray-top) tube • Serum separator tube (SST) • Polymer gel separation tube

Methodology
Enzymatic Assay (EZA)

Setup Schedule

A.M.

Clinical Significance

Overexposure/Poisoning Determination; Biomarker

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.