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Test Code Tryptophan Tryptophan

Clinical System Name

Tryptophan Level

Synonyms

None specified

Sample Requirements

Specimen: Whole Blood

Container(s): Dark Green/Sodium Heparin or Lavender/EDTA

Preferred Vol: 4.0 mL

Minimum Vol: 0.5 mL

 

Note: Collect plasma specimens after an overnight fast (or at least 4 hours after a meal). Non-fasting samples are acceptable for pediatric patients. Sample should be processed in the lab as soon as possible after collection.

Processing Instructions

Reject due to: Gross hemolysis or specimen received at room temperature 

Spin: Y

Aliquot: Y

Temp: -20 C

Storage location: Spin sample and transfer plasma into plastic aliquot container. Freeze sample as soon as possible and store in CPA freezer send-outs rack.

 

Off-site collection: Spin sample and transfer plasma into plastic aliquot container. Freeze sample as soon as possible and transport frozen at -20 C.

Stability

Specimen Type Temperature Time
Plasma Room temp Unstable
  Refrigerated 7 d
  Frozen 30 d

 

Availability

STAT Performed TAT
N Collected daily; Set-up T, Th-F at Quest 6 - 10 d

 

Performing Laboratory

Quest Diagnostics - Nichols Institute

33608 Ortega Highway
San Juan Capistrano, CA 92690-6130
 

Phone Number: (800) 553-5445

Department

Department:  Send Outs

 

Phone Number: (206) 987-2563

 

 

Reference Range

 

Age umol/L
<1 month 17-85
1 month - 23 months 16-92
2 years - 17 years 30-94
Adult 40-91

 

Methodology

Method: None LC/MS

Analytical Volume: 0.25 mL plasma

Limitations:

CPT Codes

82131

Send Out Instructions

 

Reference Test Name: Tryptophan LC/MS
Reference Test Number: 959
Instructions: Send out M - F with Quest courier.