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HelpTest Code TBGI Thyroxine-Binding Globulin (TBG), Serum
Specimen Required
Patient Preparation: For 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
CMH COLLECTION: 2 mL in red gel vacutainer
Specimen Minimum Volume
0.35 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 30 days |
Useful For
Cases in which total thyroid hormone levels do not correlate with the 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