Free and Total Carnitine, Quantitative by LCMSMS, Plasma

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FREE AND TOTAL CARNITINE, QUANTITATIVE BY LCMSMS, PLASMA

TURNAROUND TIME:   3 - 4 days
 
PERFORMED :  Tuesday and Friday  
 
TESTING METHODOLOGY:  High Performance Liquid Chromatography Triple Quadrupole Mass Spectrometer (LC/MSMS).
 
SPECIMEN REQUIREMENTS:
  • Collect:  Green (Sodium or Lithium Heparin).
  • Min. Collection: 3.0 mL whole blood
  • Transport: Separate plasma from cells ASAP or within 2 hours of collection and freeze immediately. CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered to avoid freeze/ thaw cycles.
  • Stability: After separation from cells: Ambient: Unacceptable; Refrigerated: 12 hours;  Frozen: 1 month (Avoid repeated freeze/thaw cycles)
  • Unacceptable Conditions: Specimens at Room Temperature for more than 2 hours; Specimens refrigerated more than 12 hours.
REFERENCE INTERVAL:
 
Normal ranges are based upon literature values and expert opinion.
 
Analyte
µmol/ L)
 Free Carnitine
22-55
 Total Carnitine
35-90
 Esterified Carnitine
4-36
 Esterified/ Free Ratio
0.1-0.8
 
Total and Free Carnitine are used to derive the concentration of esterified carnitine mathematically.
 
INTERPRETATIVE DATA:
Clinical correlation is necessary for appropriate interpretation of results.  Additional required information includes age, gender, diet (e.g., TPN therapy), drug therapy, and family history. Clinical information should be included on the Biochemical Genetics Test Requisition Form.
 
Analytic Sensitivity: >99%
 
Test Limitations: Separation of cells from plasma and frozen within 2 hours of collection is required for optimal test results.
 
INDICATIONS FOR USE: Intended to aid in the diagnosis and clinical management of patients with primary carnitine deficiencies or secondary carnitine deficiencies associated with organic acidurias, fatty acid oxidation disorders, or other inborn errors of metabolism associated with carnitine deficiencies.
 
ADDITIONAL RESOURCES:
 
Genetics Home Reference:  www.ghr.nlm.nih.gov
 
Metabolic and Information Center: www.metagene.de