Specimen Requirements
Title
THYROXINE-BINDING GLOBULIN (TBG)
Specimen Requirement
1 SST/1.0 mL serum. After 30 minutes of clotting, promptly centrifuge and refrigerate serum
Methodology
Stability
Room Temperature Unacceptable, Refrigerated 2 days, Frozen 14 days
Reference Range
By Report*
Turnaround
2 days Performed Mon-Fri
Clinical Use
Determine binding capacity for T4; document cases of hereditary deficiency of TBG, in work-up of thyroid disease, particularly in patients with low T4, high T3 (uptake) who clinically seem eumetabolic. Such patients may have hereditary anomalies of TBG and may not require treatment
Test Code
TBGW