Triiodothyronine, Free (Free T3)
0070133
Ordering Recommendation
Not recommended for routine thyroid screening.
Mnemonic
FT3
Methodology
Quantitative Electrochemiluminescent Immunoassay
Performed
Sun-Sat
Reported
Within 24 hours
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Specimen Required
- Patient Preparation
- Collect
- Serum separator tube or plasma separator tube. Also acceptable: Lavender (EDTA) or pink (K2EDTA).
- Specimen Preparation
- 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)
- Storage/Transport Temperature
- Refrigerated.
- Unacceptable Conditions
- Grossly hemolyzed specimens.
- Remarks
- Stability
- After separation from cells: Ambient: 5 days; Refrigerated: 1 week; Frozen: 1 month
Reference Interval
0-3 days | 2.0-7.9 pg/mL |
4-30 days | 2.0-5.2 pg/mL |
1-24 months | 1.6-6.4 pg/mL |
2-6 years | 2.0-6.0 pg/mL |
7-17 years | 2.9-5.1 pg/mL |
18 years and older | 2.4-4.2 pg/mL |
Interpretive Data
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0070133 | Triiodothyronine, Free (Free T3) | 3051-0 |
Aliases
- 3, Free, Serum
- Free T3
- Free T3 Only, S
- Free Triiodothyronine
- FT3
- T3, Free