Thyroxine (T4) Free
Test Code
FRT4
Description
Collect
Plain red top or SST tube.
Pediatric Collection
Minimum volume: 0.3mL serum
Unacceptable Conditions
Grossly hemolyzed, icteric, and lipemic specimens
Storage Transport Temp
Offsite: Send frozen serum Priority Overnight via FedEx and in a well insulated container on dry ice.
Stability
Stability after cell separation:
24 hours at RT (15-25°C)
6 days refrigerated at 2-8°C
>6 days ≤ -10°C (avoid multiple freeze / thaws)
Performed
Mon-Fri
Methodology
2 Step Competitive with Labeled Antibody Chemiluminescent
Turnaround Time
Results same day if samples are received prior to 6PM
Department
Core Lab
Synonyms
Free T4 (Thyroxine, free, serum);FRT4
Reference Interval
0.6 - 1.1 ng/dL
CPT Code
84439