Test Code T3F 
Methodology Electrochemiluminesence 
Description Useful for: T3 Free is used to diagnose hyperthyroidism and to clarify thyroid status in the presence of a possible protein binding abnormality.

No sample should be collected on patients receiving therapy with high biotin doses (i.e. biotin therapy for Multiple Sclerosis or oncology patients; skin, hair and nail supplements, or multivitamins containing > 5 mg/day) until at least 12 hours after the last biotin administration. If unsure, or if the clinical picture does not fit the results please contact the laboratory . We have methods to check for biotin interference as well as for any other interferences and for the accuracy of the results.

Biotin interference would falsely increase the result of this assay. 

Specimen Draw blood in either a plain red-top or serum gel tube. Spin down and send 1.0 mL (minimum: 0.5 mL) of serum refrigerated in a plastic screw-capped vial. 
Reference Values 0 - 19 years: 1.5 - 6.4 pg/mL (Reference ranges for infants and children are suggested ranges)
> 19 years 2.3 - 4.2 pg/Ml 
Analytic Time 1 Day 
Day(s) Test Set Up Monday through Sunday 
CPT Code(s) 84481