Test Code TBGI Thyroxine-Binding Globulin (TBG), Serum
Specimen Required
Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL serum
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
CMH COLLECTION: 2 mL in red gel vacutainer
Specimen Minimum Volume
Serum: 0.35 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 7 days |
| Frozen | 30 days |
Useful For
Cases in which total thyroid hormone levels do not correlate with thyrometabolic status, most commonly with pregnancy or the use of contraceptive steroids
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
Day(s) Performed
Monday, Wednesday, Friday
Report Available
1 to 3 daysReporting Name
Thyroxine Binding Globulin, SReference Values
Males: 12-26 mcg/mL
Females: 11-27 mcg/mL
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html
Method Name
Solid-Phase Chemiluminescent Assay
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84442