Feb 8, 2018




Clinical Hub,Tools & Resources,UWHC Lab Test Directory,Chemistry

T3, Free

T3, Free (FT3) Chemistry Lab Test

Name: T3, Free

Test Name: T3, Free

Health Link Test Code: FT3

LIS Test Code: FT3

CPT Code(s): 84481

Methodology: Chemiluminescent Immunoassay

Days Performed: Daily, 24 hours.

In-Lab Turnaround Time: 4 hours.

Stat In-Lab Turnaround Time: 1 hour.

Specimen: Blood

Collection Container: Green cap with yellow ring (PST)

Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: 2 mL

Pediatric Collection Volume: 0.4 mL

Stability Refridgerated:

6 days

Stability Frozen:

>6 days

Sample Analyzed: Plasma or serum

Testing Volume: 1 mL

Pediatric Testing Volume: 0.2 mL

Specimen Processing:

Centrifuge. If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial. Refrigerate.

Specimen Transport:

Transport specimen to the laboratory. Transport with coolant pack if coming from clinic location.


 Age  pg/mL
4 days-11 months 2.3-4.9
1 year-11 years 2.8-4.4
12-14 years

Male: 2.9-4.3

Female: 2.5-4.0

15-17 years

Male: 2.3-3.9

Female: 2.3-3.7

18 years and up


Interpretation Type: Reference Interval