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HelpTest Code LAB3523 Tryptophan Level
Additional Codes
Tryptophan
Clinical System Name
Tryptophan Level
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin, Lt. Green/Lithium Heparin
Preferred Vol: 1.0 mL
Minimum Vol: 0.5 mL
Note: Serum and EDTA plasma are also acceptable but not preferred. Collect plasma specimens after an overnight fast (or at least 4 hours after a meal). Non-fasting samples are acceptable for pediatric patients.
Processing Instructions
Reject due to: Gross hemolysis
Spin: Y
Aliquot: Y
Temp: -20 C
Storage Location: -20 C BCG Box
Off-site Collection: Spin and separate whole blood within 1 hr of collection. Freeze plasma/serum and ship frozen.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma | Room Temp (whole blood) | < 1 h |
| Room Temp (serum/plasma) | <2 h | |
| Refrigerated (serum/plasma) | 24 h | |
| Frozen (plasma/serum only) | 1 m |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | M-F | 2-5 d |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
CPT Codes
82139
Methodology
Method: high pressure liquid chromatography using an ion exchange column
Analytical Volume: 0.1 mL Plasma
Limitations:
Reference Range
|
Reference Range(s) |
|
| 0 - 1 m | 17-85 umol/L |
| 1 m - 6 y | 16-92 umol/L |
| >6 yr | 30-94 umol/L |