Thyroxine (T4) Free
Additional Codes
LAB127
Performing Laboratory
MBMC Main Laboratory
Methodology
Electro-Chemiluminescent Immunoassay (ECLIA)
Specimen Requirements
Preferred Specimen Type: Plasma
Container/Tube: Mint-green top (lithium heparin gel)
Specimen Volume: Full tube
Alternative Specimen Type: Serum
Alternative Container/Tube: Gold, Serum gel
Alternative Specimen Volume: Full tube
Specimen Transport Temperature
Ambient
Day(s) Test Set Up
Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: within 4 hours
Reference Values
0-4 days: 1-3 ng/dL
4-30 days: 0.8-2.2 ng/mL
>30 days: 0.9-1.7 ng/dL
Test Classification and CPT Coding
Test Classification:This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer’s instructions.
CPT Code:
84439
Stability
5 days Refrigerated