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Test Code 0991 T3 (Triiodothyronine), Free, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Cobas ECLIA electrochemiluminescence

Literature References:

Package Insert: Free Triiodothyronine, FT3III. Roche Corporation 04/2013.

Specimen Requirements

Specimen Type: Plasma
Container/Tube: mint green-top (lithium heparin) tube
Specimen Volume: Full tube


Day(s) Test Set Up

Monday through Sunday
Turnaround Time:
STAT: not available

Routine: 2-4 hours of receipt

Reference Values

2.0-4.4 pg/mL

Literature Reference:

Tietz Fundamentals of Clinical Chemistry, 5th Edition, Editors: Burtis CA and Ashwood ER, Chapter 55, p. 1935. W.B. Saunders Company, 2014

Test Classification and CPT Coding


Additional Information

For BJH Laboratory Use Only

Alternate Tube(s):

1 Dark-green top (lithium heparin)

1 plain, red-top tube

Separator gel tube is acceptable

Analyte Stability:

1. Do not use specimen that has been stored at ambient temperature for >8 hours.
2. Tightly cover and refrigerate specimen at 2° C to 8° C if the assay is not completed within 8 hours.
3. Freeze specimen at ≤-20° C if the specimen is not assayed within 48 hours.

Laboratory Processing Instructions:

Test performed in BJH Core Lab.  Processed by automated line for delivery to the Cobas 8000. Completed specimens are stored refrigerated for 5 days.

Specimen Transport Temperature


LOINC Code Information

Name LOINC Code
T3, Free, Plasma 3051-0