Ordering Recommendation

Not recommended for routine thyroid screening; for initial thyroid disorder screening, refer to Thyroid Stimulating Hormone (0070145).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube or plasma separator tube. Also acceptable: Lavender (K3EDTA or K2EDTA ), pink (K2EDTA), or green (lithium heparin)

Specimen Preparation

Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP standard transport tube. (Min: 0.5 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Grossly hemolyzed specimens.

Remarks
Stability

After separation from cells: Ambient: 5 days; Refrigerated: 1 week; Frozen: 1 month

Methodology

Quantitative Electrochemiluminescent Immunoassay

Performed

Sun-Sat

Reported

Within 24 hours

Reference Interval

Effective February 22, 2022

0-3 days 2.0-7.9 pg/mL
4-30 days 2.0-5.2 pg/mL
1-24 months 1.6-6.4 pg/mL
2-6 years 2.0-6.0 pg/mL
7-11 years 2.7-5.2 pg/mL
12-19 years 2.3-5.0 pg/mL
20 years and older 2.5-4.3 pg/mL

Interpretive Data



Compliance Category

FDA

Note

Hotline History

N/A

CPT Codes

84481

Components

Component Test Code* Component Chart Name LOINC
0070133 Triiodothyronine, Free (Free T3) 3051-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • 3, Free, Serum
  • Free T3
  • Free T3 Only, S
  • Free Triiodothyronine
  • FT3
  • T3, Free
Triiodothyronine, Free (Free T3)