| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
T4, Free (Thyroxine, Free)
Test CodeLAB127
Alias/See Also
Free T4, FT4
CPT Codes
84439
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
Enzyme Immunoassay
Setup Schedule
Mon- Sun
Reference Range
0.46-1.42 ng/dL
Clinical Significance
Free T4 and free T3 regulate normal growth and development by maintaining body temperature and stimulating
calorigenesis. In addition, free T4 and free T3 affect all aspects of carbohydrate metabolism as well as certain areas
of lipid and vitamin metabolism. Fetal and neonatal development also requires thyroid hormones
calorigenesis. In addition, free T4 and free T3 affect all aspects of carbohydrate metabolism as well as certain areas
of lipid and vitamin metabolism. Fetal and neonatal development also requires thyroid hormones
Performing Laboratory
Piedmont Athens Regional
