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HelpTest Code LAB2896 Carnitine Free and Total, blood
Clinical System Name
Carnitine Free and Total, Blood
Synonyms
CarnFreTo
Description
Measurement of free, acylcarnitine and total carnitine by ESI-MS/MS using stable isotope internal standards
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin, Lt. Green/ Lithium Heparin, Gold SST, Red
Preferred Vol: 1.0 mL
Minimum Vol: 0.5 mL
Note: EDTA plasma or Serum is also acceptable.
Processing Instructions
Reject due to: Gross Hemolysis
Spin: Y
Aliquot: Y
Temp: -20 C
Storage location: CPA -20C Freezer, Biochemical Genetics Box
Off-site collection: Freeze and ship heparinized plasma or serum (preferred sample type), EDTA plasma acceptable.
Stability
| Temperature | Time |
|---|---|
| Room temp | 5 days |
| Refrigerated | 5 days |
| Frozen (-20C) (serum/plasma) | 1 month |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | T, F | 3-7 days |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
Methodology
Method: Tandem mass spectrometry
Analytical Volume: 0.2 mL
Limitations:
CPT Codes
82379
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy, and family history)
Clinical Utility
Carnitine is quantitated for the purpose of follow-up in patients with organic acidurias or fatty acid oxidation disorders who may become carnitine deficient, those on valproate or other drugs that bind to and deplete carnitine, those on hyperalimentation or dialysis, and those on supplemental carnitine.
Reference Ranges
| mcmol/L | < 1 wk | 1 wk - 1 mo | > 1 mo |
| Total Carnitine | 17 - 41 | 20 - 59 | 29 - 84 |
| Free Carnitine | 10 - 33 | 16 - 57 | 18 - 65 |
| Acylcarnitine | 3 - 24 | 4 - 24 | 4 - 28 |
| Acyl/Free ratio | 0.2 - 1.4 | 0.2 - 0.5 | 0.1 - 0.8 |