Thyroxine, Total

Overview

  • EPIC Code:
  • LAB126
  • Soft Test Code:
  • T4
Alternate Names
  • T4
  • T4 Total
  • Thyroxine (T4)

Specimen Collection & Preparation

Specimen Requirements:

-OR-

1.0 mL Plasma from a PST Mint Green Top Tube - Lithium Heparin
Minimum Volume:
0.2 mL Plasma*

* This volume does not allow for repeat testing

Transport and Storage:
  • Ambient (18-24°C): 4 Days
  • Refrigerated (2-8°C): 8 Days
  • Frozen (-20° C or colder): 12 Months

Clinical Interpretation

Reference Range:

1 day to 8 days: 12.4 - 24.0 ug/dL
8 days to 1 month: 8.2 - 16.6 ug/dL
1 month to 1 year: 7.2 - 15.6 ug/dL

Male, 1 year and older: 4.5 - 12.1 ug/dL
Female, 1 year and older: 4.8 - 13.9 ug/dL


Test Comments:

This assay utilizes biotin technology. Patients taking vitamin supplements containing high doses of biotin (> 5 mg/day) may have falsely increased test results generated.


Methodology:
  • Enzyme Emit Homogenous Immunoassay

Production Schedule

Sites Performed
  • Parkview Regional Medical Center
Days Performed
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Chemistry
Turn Around Time

Same Day/1 to 2 days


Coding & Compliance

CDM

01484223


CPT Coding

84436


Medical Necessity May Apply