Direct Free T4 RIA by Equilibrium Dialysis



Free Thyroxine Hormone RIA Test Kit by Equilibrium Dialysis using the QD-Cell™ system.


The free thyroxine by equilibrium dialysis RIA Test Kit is a radioimmunoassay for direct measurement of free thyroxine (T4) after equilibrium dialysis. The dialysis is performed using a QD-Cell™ Disposable Quantitative Dialysis Cell.
Sample Preparation:
200 µL of a sample and 1350 µL of dialysis buffer are added to a sample and buffer compartment. The serum sample is allowed to dialyze for 17 hours at 37°C. 700µL of dialysate is then used in an RIA procedure for determining the concentration of free T4.
Free T4 RIA by Equilibrium Dialysis Kit


Limit of detection: <0.1 ng/dL
Limit of quantification: 0.2 ng/dL
Analytical measurement range: 0.2 – 12.8 ng/dL

Procedure Overview:

  1. Overnight dialysis of samples.
  2. One hour incubation of dialysate, standards, and controls with anti-thyroxine and I125-labelled thyroxin.
  3. Thirty minute incubation on ice.
  4. One hour incubation with second antibody
  5. Centrifuge, decant, then count.
KitCatalog Number
Free T4 RIA by Equilibrium Dialysis (Human)DFT4-2000-100/500
Vet Free T4 RIA by Equilibrium Dialysis DFT4-2000V-100/500