Preferred Sample Type
Suitable Specimen Types
- Serum
4 mL of blood (abs min 300uL serum, 900ul if PEG/dilution studies required)
Specimen Transport
First Class Post
Sample Processing in Laboratory
No special requirements
Sample Preparation
Centrifuge and separate serum.
Turnaround Time
28 daysSample Stability
4ºC
Equilibrium Dialysis free T4 (EDFT4)
General Information
Equilibrium dialysis free T4 is considered analytically accurate and is the method against which others fT4 methods are compared. Direct dialysis physically separates free thyroxine from protein-bound thyroxine. The free component is then measured directly and so is free from interference from antibodies.
This test is only required when the routinely measured thyroid results do not fit the expected pattern or clinical picture.
Patient Preparation
None
Notes
Also called EDFT4. Send clinical details and any previous thyroid function test results including assay method.
Reference Range
Provided by Reference Laboratory
Specifications
- EQA Scheme?: No
-
EQA Status:
None Available - sample exchange