T3 uptake

Alphabetical Test listing

T3 uptake-994

  
T3 uptake
  
994
  
LAB994
  
MSO
  
  • Thyroid function test for the diagnosis of hypothyroidism or hyperthyroidism, used with thyroxine (T4) or equivalent to provide free T4 index, FTI.
  • An indirect measure of binding protein, the T3 uptake reflects available binding sites (ie, reflects TBG).
  • T3 uptake is not a measurement of serum T3. It should never be used alone; rather, its usual application is use with thyroxine (T4).
  

Biotin supplements may interfere with assay.

It is recommended that patients abstain from any biotin containing supplement for 12 - 24 hours prior to blood draw. Biotin is commonly found in hair, skin and nail supplements and multivitamins.

  
Serum
  
  
1.0 mL (adult) or 0.8 mL (pediatric)
  
0.3 mL
  

Spin

  

Gold serum separator (SST) tube

  
  

Spin and separate

  
  

Ambient (preferred) - 14 days

Refrigerated - 14 days

Frozen - 14 days

  
LabCorp Burlington (001156): R-NX
  
Daily
  
1 - 3 days
  

Electrochemiluminescence Immunoassay (ECLIA)

  

An interpretive report will be provided

  
Biotin interference - see Patient preparation
  
84479
  
Yes
  
  
05/20/2019
  
11/13/2019