T-Uptake

Test Code: TD_2817

CPT Code(s): 84479

$10

Test Details

Alternative Name(s)

T3 Uptake
Thyroxine Binding Capacity
TBI

Test Includes

T-Uptake
Thyroxine Binding Capacity

Methodology

Roche COBAS Electrochemiluminescence Immunoassay (ECLIA)

Rejection Criteria

More than one freeze/thaw cycle

Reference Range(s)

T-Uptake %: 24.3-39.0
TBC: 0.8-1.3

Specimen Requirements

Preferred Specimen

Serum Separator Tube

Minimum Volume

0.5 mL serum

Sample Stability

8 days room temperature
2 weeks refrigerated
2 years frozen

Transport Temperature

Refrigerated

Collection Instructions

Allow SST to clot in an upright position for
at least 30 minutes, then centrifuge sample within 2 hours
of collection. Refrigerate.
Do not collect samples from patients receiving therapy
with high biotin doses (>5 mg/day) until at least 8 hours
following the last biotin administration.

Alternative Specimen

2 mL serum from a plain red top tube. Allow sample to clot in an upright position for at least 60 minutes, then centrifuge sample and transfer serum to a plastic transport tube within 2 hours of collection. Clearly label tube as serum from a plain red top tube. Refrigerate. Do not collect samples from patients receiving therapy with high biotin doses (>5 mg/day) until at least 8 hours following the last biotin administration.