T3 (TRIIODOTHYRONINE) UPTAKE

Test Documentation
Components
T3 Uptake is of little clinical value alone; it is used with Total T4 to determine the Free Thyroxine Index. Also see Thyroid Profile (T7)/Free Thyroxine Index (FTI)

Specimen Required
Draw blood in a SST. Centrifuge, separate and send 1.0 mL serum (0.5 mL minimum) refrigerated in a screw-capped plastic vial.

Alternate Specimen
Serum: Red-top

Rejection Criteria
Grossly hemolyzed or lipemic specimens, plasma

Methodology
Chemiluminescence

Stability
Room Temperature: 8 hours; Refrigerated: 72 hours; Frozen: 14 days

Reference Range
23-37.0%

Performed
Monday-Friday

Turnaround Time3 days
Test CodeT3U
CPT-4 Code (s)
84479
LOINC Codes
3050-2

Warde
Medical
Laboratory