Test Code FREET3 Free T3
Additional Codes
LAB137
Methodology
Used to monitor thyroid function. Measures the amount of T3 not bound to globulins. Measurement of Free T3 is useful when Total T3 is altered due to changes in thyroid hormone binding proteins. Elevated serum Free T3 values are seen in hyperthyroidism.
Performing Laboratory
St. Mary's Regional Medical Center-Chemistry
CPT: 84481
Specimen Requirements
Submit only 1 of the following specimens:
Plasma
Container/Tube: Light green-top (lithium heparin) tube
Specimen: 1 mL of lithium heparin plasma
Transport Temperature: Ambient
Collection Instructions:
Note:
1. Indicate plasma.
2. Label specimen appropriately (plasma).
Serum
Container/Tube: Plain, red-top tube or serum gel tube
Specimen: 1 mL of serum
Transport Temperature: Ambient
Collection Instructions:
Note: 1. Indicate serum.
2. Label specimen appropriately (serum).
Reference Values
01-23 months: 3.34-5.24 pg/mL
02-12 years: 3.31-4.88 pg/mL
13-20 years: 2.91-4.53 pg/mL
>20 years: 2.18 - 3.98 pg/mL
Day(s) Test Set Up
Monday through Sunday