Carnitine acylcarnitine profile (plasma)
This test measures various forms of carnitine and fatty acid-carnitine compounds in your blood plasma. It helps assess how well your body is converting fats into energy and identifies potential issues with fatty acid metabolism.
["This test can help diagnose metabolic disorders affecting fat metabolism."]
Key facts at a glance
- LOINC
- 97182-0
- Short code
- CARNP
- Synonyms
- Carnitine + acylcarnitine Pnl SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum separator tube (SST) or green-top (heparin) plasma tube; Avoid hemolysis
- Units
- N/A
- Ref low
- 25
- Ref high
- 60
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 82379
- SNOMED
- 399066001
- Specimen volume
- 1.0 mL serum or plasma; Minimum 0.5 mL acceptable for pediatric patients
- Stability
- Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days; Ambient temperature: 24 hours; Avoid repeated freeze-thaw cycles
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 48–168 hours
- Order
- routine
Why This Test Is Done
Doctors may order this test if you have symptoms like muscle weakness, fatigue, or unexplained vomiting, especially if they suspect a genetic disorder affecting carnitine or fatty acid metabolism. It’s also used in newborn screening for certain metabolic conditions.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the test to ensure accurate results. Bring any medications you’re taking to your doctor’s office.
What the Test Measures
The test detects different acylcarnitines (fatty acid-carnitine complexes) and free carnitine in your blood. Each form may indicate a specific metabolic pathway or disorder.
Common Conditions Linked to This Test
Abnormal results may signal conditions like medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, or other inherited metabolic disorders.
Reference range
Free carnitine: 25-60 umol/L; Total carnitine: 34-86 umol/L; Acylcarnitine ratio (C2 + C16:1OH)/C0: <0.4; Individual acylcarnitine species vary; Reference ranges established per individual acylcarnitine measuredN/A
No special preparation required; Fasting is not mandatory but may be recommended for evaluation of certain metabolic conditions; Patient should be advised to avoid carnitine supplements 24 hours prior to collection if clinically appropriate; For newborn screening, sample should be collected after 24 hours of feeding
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Identifying Metabolic Disorders Early
Short name
Carnitine acylcarnitine panel
Frequently asked questions
What does a high or low level of a specific acylcarnitine mean?
Can diet changes affect these results?
Is this test painful or uncomfortable?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy