Laboratory Services
Thyroxine, Free (FT4)
Print this pageUpdated Test Information:
| Test Description |
Thyroxine, Free (FT4)
|
|
|---|---|---|
| Synonym(s) |
FT4, Free T4
|
|
| Test ID |
FT4
|
|
| Specimen Type |
Serum
|
|
| Specimen Requirements |
SST
|
|
| Alternate Specimen Type |
Red, Li‑heparin, K2‑EDTA and K3‑EDTA plasma
|
|
| Minimum Sample Volume |
1 mL
|
|
| Pediatric Min. Volume (if applicable) |
500 uL
|
|
| Stability |
5 days at 20‑25 °C,
7 days at 2‑8 °C, 30 days at ‑20 °C (± 5 °C) Freeze only once |
|
| Methodology |
electrochemiluminescence immunoassay “ECLIA”
|
|
| Estimated TAT |
0-2 days
|
|
| Testing Schedule |
Monday-Saturday
|
|
| CPT Code(s) |
84439
|
|
| Reference Range |
0.82-1.7 ng/dL
|
|
| Performing Lab |
Incyte Diagnostics
|
|
| LOINC Code(s) |
3024-7
|
