Ordering Recommendation

Not recommended for routine thyroid disorder screening; for initial 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 green (lithium heparin). Also acceptable: lavender (K2 EDTA or K3 EDTA), or pink (K2 EDTA).

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: 4 days; Refrigerated: 8 days; Frozen: 1 year

Methodology

Quantitative Electrochemiluminescent Immunoassay (ECLIA)

Performed

Sun-Sat

Reported

Within 24 hours

Reference Interval

Test Number
Components
Reference Interval
  Thyroxine, Total T4
Cord Blood 6.60-17.50 ug/dL
0-3 days 5.37-22.40 ug/dL
4-30 days 5.24-23.20 ug/dL
1-23 months 5.37-16.00 ug/dL
2-6 years 5.26-14.80 ug/dL
7-11 years 5.70-14.10 ug/dL
12-19 years 4.74-14.60 ug/dL
20 years and older 4.50-11.70 ug/dL

Interpretive Data



Compliance Category

FDA

Note

Hotline History

N/A

CPT Codes

84436

Components

Component Test Code* Component Chart Name LOINC
3005980 Thyroxine, Total T4 3026-2
* 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

  • Syn-thyroid
  • T4
  • T4 serum
  • T4 total only
  • Tetraiodothyronine
  • Thyroid hormone
  • Thyroxine (T4)
  • Total T4
Thyroxine, Total T4