Carnitine
Use
Serum carnitine analysis is useful in the diagnosis and monitoring of patients with carnitine deficiency, whether primary (an autosomal recessive condition affecting cellular uptake via a defective carnitine transporter) or secondary (due to disease states, carnitine-poor diets, or metabolic disorders in which acylcarnitine esters are excreted, depleting free carnitine).
Special Instructions
Specimen must be accompanied by a special Quest Metabolic Newborn Screen Follow‑Up Test Requisition Form (TRF) with the CDPH Quest client account number when submitting. Avoid hemolysis during specimen handling.
Limitations
Moderate to gross hemolysis may lead to rejection. Performance and analytical characteristics were determined by Quest Diagnostics; the assay has not been FDA cleared or approved but has been validated under CLIA regulations for clinical use.
Methodology
Mass Spectrometry
Biomarkers
Result Turnaround Time
4-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL (0.5 mL minimum)
Minimum Volume
0.5 mL
Container
Gold top (serum) tube; plain red top tube; sodium heparin (green‑top) plasma tube also acceptable
Collection Instructions
Separate serum by centrifugation, avoid hemolysis, remove and freeze immediately. Accompany with special TRF and CDPH Quest client account number.
Patient Preparation
Patient should be in a well‑fed state
Causes for Rejection
Moderate and gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 5 hours |
| Refrigerated | 5 days |
| Frozen | 30 days |
Other tests from different labs that may be relevant