Test Directory

Test Code
FT3
Test Name
T3, Free
CPT Codes
84481
Expected Turnaround Time
1 day
Clinical Utility
Used in the evaluation of thyroid function and thyroid disorders.
Specimen and Container Info

Specimen Types: Serum or Plasma

Collection Containers:

  • Gold Top, Serum Separator
  • Light Green Top, Plasma Separator
  • Red Top, Separator

Minimum Acceptable Volume: 0.8 mL

Processing and Submission Instructions

Separator tubes: Contains clot activator and gel for separating serum from cells, but not anticoagulant. Separate serum from cells as soon as the clot has formed (30 minutes). If specimen is centrifuged before clotting is complete, a fibrin clot will form on top of the cell. This may cause the gel barrier to not be intact and could cause improper separation of serum and cells, possibly affecting test results.

Transport Instructions

Transport to the laboratory refrigerated.

Stability Requirements

Refrigerated

48 hours

Methodology
Chemiluminescent Immunoassay
Reference Intervals
Performing Location
Roble Road Core Laboratory
Testing Schedule
Routine, daily