Preferred Sample Type


Suitable Specimen Types

  • Li Hep Plasma
0.5mL blood (2 x paed Lith Hep tubes) or blood spot card (4 spots required)

Specimen Transport

Room Temperature on transport

Sample Processing in Laboratory

Store frozen prior to shipment

Sample Preparation

If blood spot has not been prepared on the ward, prepare blood spot from heparin blood on sample bench. If no blood spot cards are available, send sample to Referral Laboratory as whole blood. If taken onto blood spot cards, 4 blood spots are required

Turnaround Time

2-3 weeks

Sample Stability

Store frozen prior to shipment. Send to Referral Laboratory ASAP.


General Information

Acylcarnitine species are normal intermediates in the metabolism of fatty acids. Generally only small amounts of long chain species (C16, C18:2, C18:1) are present along with acetyl (C2) carnitine and free carnitine (C0). Small amounts of propionyl- (C3) and butyryl-(C4) may also be seen in healthy subjects. When there is a metabolic block in the metabolism of fatty or other organic acids, characteristic acylcarnitine species accumulate in biological fluids. The pattern of acylcarnitines, as determined by tandem mass spectrometry (MS/MS), is often diagnostic. There are some drug intereferences known e.g Pivalic acid, the metabolite of the antibiotic pivampicillin, (it generates pivaloyl carnitine in vivo which has the same mass as isovaleryl carnitine) and Valproic acid (the formation of valproylcarnitine in patients treated with this drug may give false positives for MCADD)

Most disorders of fatty acid beta-oxidation and several organic acidurias can be diagnosed by acylcarnitine analysis, as each enzyme deficiency causes the accumulation of specific acyl-CoAs.

The clinical symptoms of fatty acid beta-oxidation disorders are similar, including hypoketotic hypoglycemia, a Reye-like syndrome, myopathy (involving skeletal and/or heart muscle), and sudden death.

Patient Preparation



If taken onto blood spot cards, 4 blood spots are required

Reference Range

Provided by Reference Laboratory


  • EQA Scheme?: Yes
  • EQA Status:

    ERNDIN EQA Scheme

The laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital form part of the services provided by University Hospitals Birmingham and are UKAS (United Kingdom Accreditation Service) accredited to the ISO 15189:2012 standard. For a list of accredited tests and other information please visit the UKAS website using the following link:

  • Heartlands, Good Hope and Solihull Hospital pathology laboratories are a UKAS accredited medical laboratory No.8217
  • United Kingdom Health Security Agency laboratory is a UKAS accredited medical laboratory No.8213

Tests not appearing on the UKAS Schedule of Accreditation currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further test information, please visit the test database:

Protection of personal information - Laboratory Medicine comply with the Trust Data Protection policy and have procedures in place to allow the Directorate and its employees to comply with the Data Protection act  1998 and associated best practice and guidance.

For further information contact Louise Fallon, Quality Manager, 0121 424 1235