Thyroxine, Total T4
Ordering Recommendation
Not recommended for routine thyroid disorder screening; for initial screening, refer to Thyroid Stimulating Hormone (0070145).
New York DOH Approval Status
Specimen Required
Serum separator tube or green (lithium heparin). Also acceptable: lavender (K2 EDTA or K3 EDTA), or pink (K2 EDTA).
Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)
Refrigerated.
Grossly hemolyzed specimens.
After separation from cells: Ambient: 4 days; Refrigerated: 8 days; Frozen: 1 year
Methodology
Quantitative Electrochemiluminescent Immunoassay (ECLIA)
Performed
Sun-Sat
Reported
Within 24 hours
Reference Interval
Test Number |
Components |
Reference Interval |
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Thyroxine, Total T4 |
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Interpretive Data
FDA
Note
Hotline History
Hotline History
CPT Codes
84436
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
3005980 | Thyroxine, Total T4 | 3026-2 |
Aliases
- Syn-thyroid
- T4
- T4 serum
- T4 total only
- Tetraiodothyronine
- Thyroid hormone
- Thyroxine (T4)
- Total T4