ARUP's Laboratory Test Directory

Carnitine, Free & Total (Includes Carnitine, Esterified) : 0080068
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Patient History For Biochemical Genetics
  


Mnemonic: CARN F&T

Methodology: Tandem Mass Spectrometry
Performed: Tue-Sat
Reported: 1-4 days
Specimen Required: Collect: Green (sodium or lithium heparin). Also acceptable: Plain red.

Specimen Preparation: 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.

Storage/Transport Temperature: CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions: Room temperature specimens. Specimens refrigerated greater than 12 hours.

Stability (collection to initiation of testing): After separation from cells: Ambient: Unacceptable; Refrigerated: 12 hours; Frozen: 1 month (avoid repeated freeze/thaw cycles)
Reference Interval:
Age Free Carnitine Total Carnitine Esterified Carnitine Ratio Esterified: Free
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

Interpretive Data:

See Compliance Statement B: www.aruplab.com/CS
Note: The concentration of esterified carnitine is derived from a mathematical calculation using free and total carnitine.
CPT Code(s): 82379
Cross References: L-Carnitine Free & Total (Carnitine, Free & Total (Includes Carnitine, Esterified))