Useful in the diagnosis of primary carnitine deficiency (carnitine uptake defect). Monitor carnitine status.
Tandem Mass Spectrometry
New York DOH Approval Status
Green (sodium or lithium heparin). Also acceptable: Plain red.
Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 0.5 mL serum or plasma to an ARUP Standard Transport Tube and freeze immediately. (Min: 0.2 mL) Avoid hemolysis.
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.
Room temperature specimens. Specimens refrigerated greater than 12 hours.
After separation from cells: Ambient: Unacceptable; Refrigerated: 12 hours; Frozen: 1 month (avoid repeated freeze/thaw cycles)
||Carnitine, Free, Serum/Plasma||Carnitine, Total, Serum/Plasma||Carnitine, Esterified, Serum/Plasma
||Carnitine E/F Ratio, Serum/Plasma|
|1 - 31 days||15 - 55 µmol/L||21 - 83 µmol/L||4 - 29 µmol/L||0.2 - 0.8|
|32 days-12 months||29 - 61 µmol/L||38 - 73 µmol/L||7 - 24 µmol/L||0.1 - 0.8|
|13 months - 6 years||25 - 55 µmol/L||35 - 90 µmol/L||4 - 36 µmol/L||0.1 - 0.8|
|7 years -20 years||22 - 63 µmol/L||31 - 78 µmol/L||3 - 38 µmol/L||0.1 - 0.9|
|21 years or older||25 - 60 µmol/L||34 - 86 µmol/L||5 - 29 µmol/L||0.1 - 1.0|
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Laboratory Developed Test (LDT)
The concentration of esterified carnitine is derived from a mathematical calculation using free and total carnitine.
|Component Test Code*||Component Chart Name||LOINC|
|0080064||Carnitine, Esterified, Serum/Plasma||19074-4|
|0080066||Carnitine, Free, Serum/Plasma||14286-9|
|0080067||Carnitine, Total, Serum/Plasma||14288-5|
|0081148||Carnitine E/F Ratio, Serum/Plasma||40869-0|
- Esterified carnitine
- Free and Total Carnitine
- L-Carnitine Free and Total