Test Overview
Test Methodology

Chemiluminescent Immunoassay

Test Usage

Mainly of value in investigating cases of unusual binding proteins such as found in hyperthyroxinemic dysalbuminemia. Also helpful in delineating hyperthyroxinemia and hypothyroxinemia due to TBG alterations from those due to other causes.

Reference Range *

MALES: 12 - 26 mcg/mL; FEMALES: 11 - 27 mcg/mL. Pediatric values are consistent with the adult reference range.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Monday - Friday
Analytic Time

2 - 4 days

Soft Order Code
TBGI
MiChart Code
Thyroxine Binding Globulin
Synonyms
  • TBG (Immunologic)
  • TBG, Immunologic
  • Thyroxine Binding Globulin
  • TBG
Laboratory
Sendout
Reference Laboratory
Mayo TBGI (9263)
Section
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a red top or SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate.

Yellow Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.4 mL serum
Additional Information

Test sent to Mayo Medical Laboratories.

Billing
CPT Code
84442
Fee Code
22183
LOINC
3021-3
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