Sign in →

Order Code FT4 T4 (Thyroxine), Free, Plasma or Serum

Specimen Requirements

Submit only 1 of the following specimens:

 

Plasma

Draw blood in a green-top (lithium heparin) gel tube. Spin down and send 1 mL of plasma refrigerated.

Note: 1. Indicate plasma on request form.
2. Label specimen appropriately (plasma).

 

Serum

Draw blood in a plain, red-top tube or a serum gel tube. Spin down and send 1 mL of serum refrigerated.

Note: 1. Indicate serum on request form.
2. Label specimen appropriately (serum).

Reference Values

0.76-1.46 ng/dL

Performing Laboratory

Ridgeview Medical Center Laboratory

Sibley Medical Center

Day(s) Test Set Up

Monday through Sunday

Methodology

Chemiluminescence

Test Classification and CPT Coding

84439

Specimen Transport Temperature

 

Specimen Type Temperature Time
Serum/plasma Ambient 1 day
  Refrigerated (preferred) 5 days
  Frozen 5 days