Red serum vial/tube, 5 mL

or

Gold serum separator (SST) tube

Immediately following collection, mix sample by gently inverting 5 times

1. Allow sample to clot for a minimum of 30 minutes
2. Spin within 45 minutes of sample collection
3. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as serum
4. Freeze

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Lavender (EDTA), 4mL

Dk green Lithium heparin (Li hep) vial/tube (no gel) - 4 mL

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10 times to prevent clotting

1. Spin within 45 minutes of sample collection
2. Transfer serum to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as plasma
3.  Freeze

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Frozen (preferred) - 70 days

Refrigerated - 5 days

Ambient - 5 days

Whole blood

Equilibrium dialysis and high-pressure liquid chromatography/tandem mass spectrometry (HPLC/MS-MS)

See report

Direct measurement of FT3 by equilibrium dialysis, high-pressure liquid chromatography, and tandem mass spectrometry (ED-HPLC/MS-MS) provides enhanced accuracy over commonly used analog (automated) methods and is not affected by clinical conditions that impact protein binding capacity.1-4 Examples of clinical conditions in which the FT3 by dialysis and MS/MS method may be preferred include congenital absence of thyroxine-binding protein (TBG);1 pregnancy;1-5 administration of oral contraceptives or hormone therapy;6 administration of atypical antipsychotic medications;7 malignancy or other critical illnesses.