Not recommended for routine thyroid screening.
Quantitative Electrochemiluminescent Immunoassay
Sun-Sat
Within 24 hours
Serum Separator Tube (SST). Also acceptable: Plasma Separator Tube (PST), Lavender (EDTA), Pink (K2EDTA), or Green (Sodium or Lithium Heparin).
Allow specimen to clot completely at room temperature. Separate 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 of cells: Ambient: 8 days; Refrigerated: 2 weeks; Frozen: 2 years
28-41% uptake
Thyroxine, Free (Free T4) (0070138) is the preferred test alternative for T3 uptake and Free Thyroxine Index tests.
FDA
T3 uptake is of little clinical value alone; it is used to determine the Free Thyroxine Index.
84479
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0070135 | T3 Uptake | 3050-2 |
- T-Uptake
- T3 Uptake, S
- T3U, Serum
- THBR
- Thyroid Binding Ratio
- Triiodothyronine Uptake, Serum