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Test Mnemonic T4 T4 (Thyroxine), Serum


Clinical Significance:

Thyroid function test, useful in the diagnosis of hypothyroidism or hyperthyroidism.

Performing Laboratory

Hallmark Health

Physician Office Specimen Requirements

Container/Tube:  Serum gel tube(s)

Specimen:  1 mL (minimum volume:  0.5 mL) of serum

Transport Temperature:  Refrigerate

Collection Instructions:  No isotopes administered 24 hours prior to venipuncture.

Reference Values

4.50-12.0 mcg/dL