Collect: Green (sodium or lithium heparin). Also acceptable: Lavender (EDTA).
Specimen Preparation:Centrifuge immediately. Transfer 2 mL plasma to a collection tube containing 40 mg oxalic acid (ARUP supply #16569). Available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787. (Min: 1.3 mL)Mix and freeze within 1 hour of collection. Adequate preservation is 20 mg oxalic acid to 1 mL plasma.
Storage/Transport Temperature:CRITICAL FROZEN. Separate samples must be submitted when multiple tests are ordered.
Remarks:The oxalic acid preservative may interfere with other tests.
Unacceptable Conditions: Body fluids other than plasma. Hemolyzed plasma. Non-frozen specimens. Specimens not preserved with oxalic acid.
Stability (collection to initiation of testing): After separation from cells: Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen (with oxalic acid preservative added): 2 months
Reference Interval:
0.4-2.0 mg/dL
Note:
Vitamin C concentrations between 0.2 and 0.4 mg/dL indicate risk of deficiency. Concentrations less than 0.2 mg/dL are consistent with deficiency.
