Test Directory

Clear All
Test Code
OXASP
Test Name
Oxalate, Serum/Plasma
CPT Codes
83945
Expected Turnaround Time
3 - 6 days
Clinical Utility
Oxalate, Serum/Plasma - Overexposure/Poisoning Determination; Biomarker
Specimen and Container Info

Preferred Specimen Type: Serum

Alternate Specimen Type: Plasma

Preferred Collection Container: Red Top, Plain

Alternate Collection Container: Green Top (Sodium Heparin)

Desired Specimen Volume: 2 mL
Collection Instructions
  1. Collect specimen in red top tube or green top (sodium heparin) tube via venipuncture.
  2. Promptly centrifuge with refrigeration.
  3. Separate Serum or Plasma into a chilled plastic screw capped vial using approved guidelines.
  4. Freeze immediately and ship with dry ice.
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.
Transport Instructions

Transport to the laboratory frozen. 
Stability Requirements

Room Temperature

Not stable

Refrigerated

Not stable

Frozen

30 days
Causes for Rejection

Received room temperature. Received refrigerated. Sodium fluoride/potassium oxalate (gray-top) tube. Serum separator tube (SST). Polymer gel separation tube.
Methodology
High Performance Liquid Chromatography-Tandem Mass Spectrometry
Reference Intervals

See patient report.
Performing Location
Roble Road Core Laboratory
Reference Lab
NMS Labs
Testing Schedule
Varies
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
© 2026 HNL Lab Medicine. All rights reserved.