FIX is a vitamin K dependent glycoprotein synthesized by the liver. FIX can be activated to FIX in FIXa by FXIa or by FVIIa in the presence of phospholipids and calcium.
A person who is deficient in FIX has hemophilia B.
- Linearity between 0.02 and 0.8 mIU / mL
- Limit of quantification = 0.02 mIU FIXa / mIU FIX
- The sensitivity of 0.005% is much better than that of the NAPTT method
- Reagents stable 48 h at 2-8 °C
- Calibrator and control provided
The ROX FIX-A is a chromogenic enzymatic assay kit for the determination of very small amounts of FIXa in human FIX concentrates. The results are expressed in IU. The very low presence of FIXa can be measured. (Specialized hemostasis).
This method is based on the activation of FX by FIXa (considered a contaminant in FIX concentrate) in the presence of FVIII, thrombin, phospholipids and calcium ions.
The amount of FXa generated is determined by hydrolysis of a chromogenic substrate for FXa.
The quantity of para-nitroaniline released during this hydrolysis and measured at 405 nm is proportional to the concentration of FIXa in the reaction medium.
- 2 vials x reagent A (lyophilized human FVIII and FX)
- 2 vials x reagent B (lyophilized human thrombin, CaCl2 and phospholipids)
- 1 vial x FXa Chromogenic Substrate (6 mL)
- 1 vial x FIXa dilution buffer (20 mL)