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Test Code TBGI Thyroxine-Binding Globulin (TBG), Serum

Additional Codes

Epic Ordering Code LAB3041502
NBS code LBC13203
Service code 36719 

Reporting Name

Thyroxine Binding Globulin, S

Specimen Type

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.


Specimen Minimum Volume

Serum: 0.35 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  30 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK

Method Name

Solid-Phase Chemiluminescent Assay

Day(s) Performed

Monday, Wednesday, Friday

Report Available

1 to 3 days
National University Hospital-Singapore Note:

Please note that this is a referral test requiring transport to the external testing facility and an additional 3-5 days is required.

Reference 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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

CPT Code Information

84442

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TBGI Thyroxine Binding Globulin, S 3021-3

 

Result ID Test Result Name Result LOINC Value
TBGI Thyroxine Binding Globulin, S 3021-3

Secondary ID

9263

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
National University Hospital-Singapore Additional Information:

Last updated 20/07/2026