Carnitine Concentration Profile

Test Description:

Carnitine facilitates the transport of long chain fatty acylCoA across the inner mitochondrial membrane for beta-oxidation. Carnitine analysis is indicated for diagnosing or monitoring patients with primary carnitine uptake defect, fatty acid oxidation disorders, inherited organic acidemias and mitochondrial respiratory chain disorders. Carnitine deficiency can also be associated with valproic acid therapy, high dose benzoic acid treatment, some neuromuscular diseases, cardiomyopathic diseases and malnutrition. Carnitine is measured quantitatively by liquid chromatography and tandem mass spectrometry. Carnitine concentration profile reveals concentrations of free (FC), total (TC) and esterified carnitines (AC) as well as the ratio of AC/FC. The test is most commonly performed in serum or plasma. The carnitine profile can be influenced by factors such as diet, nutritional status, medication, disease status, and inappropriate sample processing. Information regarding diet, nutrition, medication and medical history should be provided with the sample for optimal interpretation. A urine carnitine profile is recommended in addition to a plasma carnitine profile in patients suspected to have a primary disorder of carnitine transport. Plasma acylcarnitine profile and urine organic acids analysis should also be performed for evaluation of a differential diagnosis.

Specimen Requirements:

Plasma: One 5 ml tube of anticoagulated blood (fasting or 2-4 hour postpranadial) in sodium heparin (green top); centrifuge immediately and freeze plasma.

Urine: 5 ml (random void) in a clean container without preservatives; freeze.


Ship overnight frozen on dry ice.

Turnaround Time: 

5 days for routine samples.

Same day results available on an emergency basis.

Please call the laboratory prior to sending a sample for STAT analysis.

CPT Codes: 80500, 82379

Consent Form: Postnatal Consent [PDF]

Requisition Form: General Test Requisition [PDF]