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Acetylcarnserplmcnc

Published: August 9, 2026Updated: August 10, 2026

This test measures the level of acetylcarnitine in your blood to help evaluate your body's energy metabolism and carnitine status.

Quick summary

{"Acetylcarnitine is a form of carnitine that helps produce cellular energy","The test is commonly used to screen for inherited metabolic disorders","It may also help assess liver function and certain neurological conditions","A blood sample is drawn from a vein in your arm","Results help doctors diagnose and monitor specific metabolic conditions"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
18436-6
Short code
AC C2
Synonyms
Acetylcarn SerPl-mCnc
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or plain red top tube
Units
N/A
Ref low
2
Ref high
8
Critical range
1 N/A – 15 N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Tandem Mass Spectrometry (LC-MS/MS)
CPT
82017
SNOMED
314255006
Specimen volume
1.0 mL serum minimum
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
Hemolysis max
50
Lipemia max
300
Icterus max
20
TAT
24–72 hours
Order
routine

What is this test?

The acetylcarnitine (C2) test measures the amount of acetylcarnitine in your serum or plasma. Acetylcarnitine is a naturally occurring molecule derived from the amino acid lysine and plays a crucial role in energy production. It helps transport fatty acids into the mitochondria, where they are burned for energy. This test is part of a broader group of tests called acylcarnitine profile analysis, which evaluates various forms of carnitine in the blood.

Why might I need this test?

Your doctor may order this test for several reasons: (1) Newborn screening - to detect inherited metabolic disorders such as carnitine palmitoyltransferase (CPT) deficiencies, (2) Evaluating symptoms like muscle weakness, fatigue, or metabolic crises, (3) Assessing liver function or heart muscle problems, (4) Monitoring patients with known metabolic disorders, or (5) Investigating unexplained hypoglycemia or cardiomyopathy. The test is particularly important for infants and children with suspected metabolic conditions.

How is the test performed?

A healthcare professional will draw a small blood sample from a vein in your arm using a needle. The blood will be collected in a tube and sent to a laboratory for analysis. The procedure only takes a few minutes and is generally well-tolerated. For newborns, the sample may be collected via a heel stick. You typically do not need to fast before this test, but follow your doctor's specific instructions.

Are there any risks?

The risks associated with this blood test are minimal and include slight pain or bruising at the needle site, lightheadedness, and in rare cases, infection. These risks are generally temporary and resolve quickly. The benefits of obtaining important diagnostic information far outweigh these minor, temporary discomforts.

Reference range

Reference range: 2.0-8.0 µmol/L (may vary by laboratory method)N/A

Specimen: serum

No special preparation required. Avoid vitamin supplements containing carnitine 24 hours prior to collection if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Do I need to fast before the test?
Typically, no fasting is required for the acetylcarnitine test. However, follow your healthcare provider's specific instructions, as some laboratories may have particular requirements based on the purpose of your test.
How long does it take to get results?
Results are usually available within 3-7 days, depending on the laboratory. Specialized metabolic testing may take longer. Your doctor will contact you with the results or discuss them at your follow-up appointment.
What happens if my results are abnormal?
An abnormal result does not always mean you have a serious condition. Your doctor will interpret the results in context of your symptoms, medical history, and other test findings. Additional testing may be needed to confirm a diagnosis. If a metabolic disorder is confirmed, treatment options are available, including dietary modifications and supplementation.
Is this test only for children?
No, while this test is commonly used in newborn screening and pediatric care, it can be ordered for patients of any age when metabolic or carnitine-related conditions are suspected. Adults may need this test if they have symptoms of metabolic disorders or certain liver and heart conditions.
  1. 1
    Mayo Clinic Laboratories - Acylcarnitine ProfileSource
  2. 2
    MedlinePlus - Carnitine DeficiencySource
  3. 3
    American College of Medical Genetics - Newborn ScreeningSource

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.

Medical Disclaimer

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 10, 2026. · Read our editorial policy