Thyroxine, Free
| Alternate Names | FT4; Free T4 |
| Ordering Recommendation | Measurements of free thyroxine, with thyroid-stimulating hormone (TSH), are used in the diagnosis and treatment of thyroid disease. |
| Specimen | Lithium Heparin Plasma |
| Container Type | Green Top Tube
|
| Methodology | Chemiluminescence |
| Reference Range | 1-23 months: 0.94-1.44 ng/dL 2-12 years: 0.86-1.40 ng/dL 13-20 years: 0.83-1.43 ng/dL >20 years: 0.89-1.76 ng/dL |
| Stability | 7 days |
| Transport Temp | Refrigerate 2°-8°C |
| Days Performed | Daily |
| Report Available | 1 day |
| NY State Available | Yes |
| LOINC Code | 3024-7 |
| CPT Code | 84439 |
