Thyroxine Binding Globulin

Alphabetical Test listing

Thyroxine Binding Globulin-13315

Test name:

Test number:

13315

Excellian order number:

LAB13315

Abbreviation:

TBG

Useful for:

Distinguish between high T4 levels due to hyperthyroidism and due to increased binding by TBG in euthyroid individuals who have normal levels of free hormones
Document cases of hereditary deficiency or increase of TBG
Work-up of thyroid disease

Specimen type:

Serum

Collection container:

Gold serum separator (SST) tube

Volume:

0.8 mL

Minimum volume:

0.5 mL
(Note: This volume does not allow for repeat testing.)

Collection instructions:

Immediately following collection, thoroughly mix sample by gently inverting 5 times

Processing instructions:

Allow sample to clot for a minimum of 30 minutes
Spin within two (2) hours of sample collection

Transport container:

Gold serum separator (SST) tube

Alternate collection container:

Red serum vial/tube, 5 mL

Alternate processing instructions:

Allow sample to clot
Spin within two (2) hours of sample collection
Transfer serum to a Transfer vial/tube with cap - 12mL (LabCorp), labelled as serum

Alternate transport container:

Transfer vial/tube with cap - 12mL (LabCorp)

Transport and stability:

Ambient (preferred) - 7 days

Refrigerated - 14 days

Frozen - 14 days

Freeze/thaw cycles - stable x3

Reason for rejection:

Gross hemolysis

Performing lab:

LabCorp Burlington (001735): R-LC

Days set up:

Daily

TAT:

1 - 3 days

Method:

Immunochemiluminometric assay (ICMA)

Reference ranges:

Age	Male (μg/mL)	Female (μg/mL)
<1 year	16−33	18−32
1 - 3 yrs	16−32	19−34
4 - 6 yrs	17−30	18−31
7 - 12 yrs	17−29	15−29
13 - 18 yrs	13−26	14−29
>18 yrs	13−39	13−39

CPT codes:

84442

LOINC code:

Result 3021-3

Date created:

04/11/2019

Revised date:

08/16/2023

Review date:

08/16/2023