Test Details
Methodology
Liquid chromatography-tandem mass spectrometry (LC/MS-MS)
Result Turnaround Time
3 - 5 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
This test is used for the evaluation of vitamin C levels.
Special Instructions
Please note that this test is to be used for patients on high-dose vitamin C (e.g., cancer therapy) in which results are expected to be very high relative to the reference interval.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Plasma, frozen and protected from light
Volume
1 mL
Minimum Volume
0.5 mL (Note: This volume does not allow for repeat testing.)
Container
Green-top (lithium heparin) tube; amber plastic transport tube with amber-top. (If amber tubes are unavailable, cover standard transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient name directly on the container and on the outside of the aluminum foil. Secure with tape.) For amber plastic transport tube and amber-top, order Labcorp No. 23594.
Collection Instructions
Collect blood by venipuncture into a green-top containing lithium heparin and mix immediately by gentle inversion at least six times to ensure adequate mixing. Plasma must be separated from cells immediately after venipuncture and transferred to light-protected amber plastic tube. Separated plasma must be placed on dry ice for shipment within 4 hours of separation. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Stability Requirements
| Temperature | Period |
|---|---|
| Room temperature | Unstable |
| Refrigerated | Unstable |
| Frozen | 14 days |
| Freeze/thaw cycles | Stable x1 |
Reference Range
0.4–2.0 mg/dL
Storage Instructions
Freeze immediately and protect from light.
Causes for Rejection
Anticoagulants other than lithium heparin; specimen not protected from light
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 123420 | Vitamin C (with dilution) | 1903-4 | 123421 | Vitamin C (with dilution) | mg/dL | 1903-4 |
| Order Code | 123420 | |||||
| Order Code Name | Vitamin C (with dilution) | |||||
| Order Loinc | 1903-4 | |||||
| Result Code | 123421 | |||||
| Result Code Name | Vitamin C (with dilution) | |||||
| UofM | mg/dL | |||||
| Result LOINC | 1903-4 |