Thyroxine (T4), Free
Order Name
FREE T4
Test Number: 4502550
Revision Date 08/12/2020
Test Number: 4502550
Revision Date 08/12/2020
| Test Name | Methodology | LOINC Code |
|---|---|---|
|
Thyroxine (T4), Free
|
Chemiluminescence Assay | 3024-7 |
| SPECIMEN REQUIREMENTS | ||||
|---|---|---|---|---|
| Specimen | Specimen Volume (min) | Specimen Type | Specimen Container | Transport Environment |
| Preferred | 1 mL (0.5) | Serum | Clot Activator SST | Refrigerated |
| Alternate 1 | 1 mL (0.5) | Plasma | Lithium Heparin PST (Light Green Top) | Refrigerated |
| Instructions | Stability: Ambient 1 day. Refrigerated 6 days. Frozen > 6 days | |||
| GENERAL INFORMATION | |
|---|---|
| Testing Schedule | Mon - Fri |
| Expected TAT | 1-3 days |
| Clinical Use | The FT4 value combined with the TSH value, gives a more accurate picture of the thyroid status in patients with abnormal TBG levels such as those who are pregnant or those who are receiving treatment with estrogens, androgens, phenytoin or salicylates. |
| CPT Code(s) | 84439 |
| Lab Section | Chemistry |