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Test Code T3 Total T3, LAB136

Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements

Container/Tube:

Preferred: Green top (Lithium Heparin)

Acceptable: Plain, red-top serum tube or Gold SST tube

Specimen Volume: 0.3 mL

Minimum volume: 0.018 mL plus dead volume

Stability:  Room temperature for 8 days, 14 days at 2 – 8 °C or 12 months frozen at -20° Celsius

Reference Values

80-200 ng/dL

Day(s) Test Set Up

Monday through Sunday

Methodology

Chemiluminescence Immunoassay

Test Classification and CPT Coding

84480

Useful For

Thyroid function

Diagnostically, T3 concentration is more sensitive to certain thyroid conditions than T4.  While T4 levels are sensitive indicator of hypothyroidism, T3 blood levels better define hyperthyroidism.

Analytical Time

STAT: within one hour of receipt

Routine: within 2 hours of receipt