Acylcarnitine, Plasma
Use
Acylcarnitine profiling in plasma is used for diagnosing inherited metabolic disorders, particularly disorders of fatty acid oxidation and organic acidurias. Elevated acylcarnitines can indicate specific enzyme deficiencies or metabolic dysfunctions, especially in newborn screening follow-up contexts. The assay supports the detection of conditions such as medium-chain and long-chain acyl-CoA dehydrogenase deficiencies, with multiple acylcarnitines measured to provide diagnostic patterns.
Special Instructions
As part of newborn screen follow-up, the specimen must be collected in a sodium heparin (green-top) tube. Serum separator (SST) or red-top tube is also acceptable. Accompanying requisition form required (Metabolic NBS Follow-Up TRF with CDPH Quest client account) and specimen must be frozen during transport. Setup is performed Sunday through Friday. Reporting available in approximately 5–6 days.
Limitations
Specimen rejection criteria include gross hemolysis, receipt at room temperature or refrigerated (specimen must be frozen), and Lithium heparin plasma. Stability constraints: specimen remains stable at room temperature and refrigerated for only 1 hour, and up to 30 days if frozen. Analytical limitations typical of acylcarnitine profiling (e.g., dietary influences, carnitine deficiency) are not explicitly stated on the Quest page.
Methodology
Mass Spectrometry
Biomarkers
Result Turnaround Time
5-6 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.2 mL
Container
Green (sodium heparin) tube; SST or red-top tube also acceptable
Collection Instructions
Serum separator (SST) or red-top tube acceptable; accompany with Metabolic Newborn Screen Follow-Up TRF with CDPH Quest client account; transport frozen
Causes for Rejection
Gross hemolysis; received room temperature; received refrigerated; Lithium heparin plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 Hour |
| Refrigerated | 1 Hour |
| Frozen | 30 Days |