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Test Code PHENOB Phenobarbital Level

Important Note

No add-ons after 8 hours of collection if specimen is still on gel separator.

Clinical System Name

Phenobarbital Level

Sample Requirements

Specimen:  Whole Blood

Container(s): Gold SST, Dark Green/Sodium Heparin, Red, Gold Microtainer, Lt. Green/Li Heparin Microtainer

Preferred Vol: 1.0 mL

Minimum Vol: 0.5 mL


Note:  Draw specimen just before next dose.


Processing Instructions

Reject due to:  Age of Specimen

Spin: Y

Aliquot: Y

Temp: 2-8oC

Storage location: Core 5 Chemistry Refrigerator


Off-site collection: Draw specimen just before next dose. Spin blood, freeze serum or plasma.



Specimen Type Temperature Time
Serum or Plasma RT


Serum or Plasma 2-8oC

 30 D

Serum or Plasma -20oC or -70oC

90 D



STAT Performed TAT
Y 24/7 1 H


Performing Laboratory

Seattle Children's Laboratory    


Department:  Core Chemistry

Phone Number: 206-987-2617

Reference Range

Therapeutic: 15 - 40 µG/mL


Method:  EMIT by Vitros 4600

Analytical Volume: 0.05 mL serum or plasma

CPT Codes


Critical Values

≥ 49.9  µG/mL