Factor XI (FXI) is a protein synthesized by the liver. It participates in the contact phase which initiates the intrinsic pathway of coagulation.
It is activated by FXIIa to factor FXIa which will itself activate FIX in the presence of calcium ions.
- Excellent sensitivity around 1.2 mIU / mL
- FXIa No FXI-deficient plasma is used
- Can be used directly without dilution after reconstitution
- Sensitivity of approximately 0.03 mIU / mL
The FIXa formed activates FX to factor FXa 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 and is proportional to the concentration of FIXa in the reaction medium. The results are expressed in IU.
The very low presence of FXIa can be measured. (Specialized hemostasis)
- 2 vials x reagent A (lyophilized human FIX and FVIII)
- 2 vials x reagent B (lyophilisate of human FX and bovine thrombin, CaCl2 and phospholipids)
- 1 vial x FXa chromogenic substrate (6 mL)
- 1 vial x dilution buffer (20 mL)
