T4

Test Code
LAB126


Alias/See Also
Thyroxine, Total T4


CPT Codes
84436

Preferred Specimen
4.5 ml (1.5 ml minimum) lithium heparin (green); alternate-SST (gold) or Red (no additive)


Minimum Volume
1 ml (500 ul minimum) plasma; alternate-serum


Instructions
After centrifugation, if not in gel barrier tube, pour off serum into an aliquot tube


Transport Temperature
Room Temp.


Specimen Stability
Separated from cells: 8 hours room temp, 48 hours refrigerated


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Icteric: >20 mg/dL bilirubin, Hemolysis: >500 mg/dL hemoglobin, Lipemia: >3000 mg/dL triolein or >500 mg/dL cholesterol


Methodology
Competitive Binding Immunoenzymatic Assay

Setup Schedule
Mon- Sun


Reference Range
4.3-11.7 µg/dL


Clinical Significance
The clinical importance of total T4 determination is in the diagnosis and confirmation of thyroid disorders


Performing Laboratory
Piedmont Athens Regional



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.