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T Uptake
Ordering Recommendation
The preferred alternative to this test is Thyroxine, Free (Free T4)
Methodology
Quantitative Electrochemiluminescent Immunoassay (ECLIA)
Performed
Mon-Sat
Reported
Within 24 hours
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation:
Collect:
Serum separator tube or green (lithium heparin). Also acceptable: lavender
Specimen Preparation:
Allow specimen to clot completely at room temperature. Separate from cells ASAP or within 2 hours of collection.
Storage/Transport Temperature:
Refrigerated.
Unacceptable Conditions:
Grossly hemolyzed specimens.
Remarks:
Stability:
After separation of cells: Ambient: 8 days; Refrigerated: 2 weeks; Frozen: 2 years
Reference Interval
Components
Available Separately
Reference Interval
Thyroxine, Total T4
0.8-1.3 TBI
Interpretive Data
Thyroxine, Free (Free T4) is the preferred test alternative for T Uptake and Free Thyroxine Index tests.
Note
CPT Code
84479
Components
Component Test Code
Component Chart Name
LOINC
3005979
T Uptake
74795-6
Aliases
T3 Uptake
T4 uptake, S
T4U, Serum
TBC
THBR
Thyroid Binding Ratio
Thyroxine-binding capacity
Throxine Binding Index
Triiodothyronine uptake, serum
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