Acetylcarndbsscnc

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of acetylcarnitine in a blood sample to evaluate metabolic function and detect certain inherited disorders.

Quick summary

{"Acetylcarnitine (C2) is a molecule that helps transport fatty acids for energy production","This test is commonly used in newborn screening to detect metabolic disorders","Abnormal levels may indicate problems with fatty acid metabolism or carnitine deficiency","The test is typically performed on a dried blood spot sample","Early detection of metabolic disorders allows for timely treatment and management"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC: 50157-7
Short code: AC C2 DBS
Synonyms: Acetylcarn DBS-sCnc
Category: chemistry
Sample: serum
Container: Dried blood spot (DBS) filter paper collection card (e.g., Whatman 903 or equivalent)
Units: N/A
Ref low: 2
Ref high: 15
Critical range: 1 N/A – 25 N/A
Fasting: false
Population: adult
Sex: all
Age range: ≥ 0 years
Method: Tandem Mass Spectrometry (MS/MS)
CPT: 82017
SNOMED: 122269009
Specimen volume: 3-4 complete circles filled with blood (approximately 75-100 μL total blood)
Stability: Room temperature (15-25°C): 7-14 days; Refrigerated (2-8°C): 30 days; Frozen (-20°C or below): >30 days; Protect from heat and humidity
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 24–72 hours
Order: routine

What is this test?

The acetylcarnitine (C2) test measures the amount of acetylcarnitine in your blood. Acetylcarnitine is a specialized form of carnitine, a molecule that plays a crucial role in energy production. Specifically, acetylcarnitine helps transport fatty acids into the mitochondria (the energy-producing centers of cells) where they are burned for fuel. This test is often performed using a dried blood spot (DBS) sample, where a few drops of blood are collected on a special filter paper and allowed to dry.

Why is this test performed?

The acetylcarnitine test is primarily used for: 1) Newborn screening to identify inherited metabolic disorders early, 2) Diagnosing fatty acid oxidation disorders that affect how the body converts fat into energy, 3) Evaluating carnitine deficiency or transport problems, and 4) Monitoring patients with known metabolic conditions. It is especially important for infants because metabolic disorders may not be apparent at birth but can cause serious health problems if not detected and treated early.

What do the results mean?

Normal acetylcarnitine levels vary by age. Elevated levels may indicate certain metabolic disorders such as medium-chain acyl-CoA dehydrogenase deficiency (MCAD), carnitine transport defects, or other fatty acid oxidation disorders. Low levels are less common but may suggest nutritional deficiencies or certain liver conditions. Your healthcare provider will interpret your results based on your age, symptoms, and other test findings.

Reference range

Reference range for Acetylcarnitine (C2) in dried blood spot: 2.0-15.0 μmol/L (typical newborn screening range); optimal: 5.0-10.0 μmol/LN/A

Specimen: serum

No fasting required; for newborn screening, specimen should be collected 24-72 hours after birth or prior to discharge; ensure proper heel stick technique for adequate blood volume

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is fasting required before this test?

For newborn screening, the test is typically done before any feeding patterns are established. For older children or adults, your healthcare provider may recommend fasting for a certain period before the test, as eating can temporarily affect fatty acid metabolism and acetylcarnitine levels. Always follow your healthcare provider's specific instructions.

How is the blood sample collected?

For newborns, a few drops of blood are usually collected from the heel and spotted onto special filter paper (dried blood spot method). For older children and adults, a standard blood draw from a vein in the arm may be used. The sample is then sent to a laboratory for analysis.

What happens if my baby's test is abnormal?

An abnormal result does not necessarily mean your baby has a serious condition. Elevated acetylcarnitine levels can sometimes be due to temporary factors. If the result is abnormal, your healthcare provider will contact you for follow-up testing to confirm or rule out metabolic disorders. Early intervention is crucial for managing any identified conditions effectively.

Are there risks associated with this test?

The risks are minimal and similar to routine blood tests. For newborns, the heel prick may cause brief discomfort or a small bruise. For venous blood draws, there may be slight pain, bruising, or rarely, infection at the puncture site.

Sources

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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 16, 2026. · Read our editorial policy