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Test Code T4T Thyroxine T4 Total

Alias

T4 Total

Collection Method

Venous Collection

Container

Light Green Lithium Heparin tube

Instructions/Special Handling

None

Preferred Specimen

Light Green (Lithium Heparin) Plasma

Acceptable Specimes

  • Serum
    • Gold SST tube
    • Red tube
  • Plasma
    • Light Green lithium heparin
    • Lavender EDTA

Units

mcg/dL

Reference Ranges

Age Reference Ranges
0 minutes - 6 days 11.0 - 21.5 mcg/dL
6 days - 1 month 8.2 - 16.6 mcg/dL
1 month - 1 year 6.5 - 14.5 mcg/dL
1 year - 5 years 6.0 - 13.5 mcg/dL
5 years - 15 years 5.0 - 12.0 mcg/dL
>15 years 4.5 - 11.7 mcg/dL

Critical Values

N/A

Reasons for Rejection

Hemolysis N/A
Icterus N/A
Lipemia N/A
Other QNS, Contaminated, Improperly labeled, Improper specimen type

 

Specimen Stability

Ambient (15-25°C) Spun within 24 hours
Refrigerated (2-8°C) 6 days
Frozen (-20°C) 12 months

 

Performing Site

Boone Health Laboratory

Performance Information

Days/Times Performed Monday, Wednesday, and Friday
Expected Turn around Time Same day
Methodology/Method Description Architect - Chemiluminescence immunoassay

CPT Code(s)

84436

CMS National Coverage Policy - Thyroid Testing

Panel Components

N/A