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Test Code T4FREE T4 (Thyroxine), Free, Serum


Chemiluminometric Immunoassay

Performing Laboratory

Aspen Valley Hospital

Physician Office Specimen Requirements

Container/Tube:  Gold-top serum gel tube(s) or orange-top tube(s) - Plasma is not acceptable.
  2 mL (minimum volume:  1 mL) of serum
Transport Temperature:  Refrigerate

Collection Instructions:  Allow specimen to clot for approximately 10 minutes and spin down. If drawing gold-top serum gel tube, send entire tube to laboratory. If drawing orange-top tube, remove serum and place in separate plastic vial. If there is a delay in transport of >48 hours, send specimen frozen.

Reference Values

0.75-1.76 ng/dL

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding