Carnitine, Free and Total, Plasma

Methodology: 
Liquid chromatography - tandem mass spectrometry (LC-MS/MS)
Performed: 
Monday - Friday (days); STAT is available after consultation with the Metabolics Laboratory director; call 352.265.9900 to make arrangements for a STAT case.
Reported: 
5 - 7 business days
Use: 

This test is used to evaluate the plasma carnitine status in individuals at risk for carnitine deficiency, due to carnitine transporter deficiency; inherited metabolic disorders; renal insufficiency; valproic acid therapy; and decreased dietary intake.

Limitations: Plasma carnitine concenteration may not correlate with carnitine concentration in tissues (see Debska-Slizien A, et al., J Ren Nutr, 2007; 17:27-81.)
Specimen Requirements: 
Type: Blood
 
Container: Heparin or EDTA
 
Sample volume: 0.5 mL
 
Minimum volume: 0.25 mL
 
Storage: Refrigerate whole blood specimens.
 
Stability (collection to time of analysis):
  • Ambient: 4 hours
  • Refrigerated: 1 day
  • Frozen: 4 weeks
Rejection criteria:
  • Frozen whole blood
  • Citrate or acid citrate dextrose (ACD) tube
CPT Code (s): 
82379
Notes: 

UFHPL Test #: 40125

Collection procedure: 
  • Venipuncture is preferred. Capillary specimens are accurate and acceptable if properly collected.
     
  • Spin specimens before refrigerating them if blood is collected in a gel tube (PST, PPT). If transport is delayed or specimens are not sent by overnight courier, spin the blood, and seperate and freeze the plasma.
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