Factor XI (FXI) is a protein synthesized by the liver. It participates in the contact phase which initiates the intrinsic coagulation pathway.
It is activated by FXIIa to factor FXIa which will itself activate FIX in the presence of calcium ions.
Calibration of the human FXIa lyophilisate was carried out using the international standard NIBSC 11/236 used in the ROX Factor XIa kit.
The ROX FACTOR XIa is a quantitative enzymatic and chromogenic assay kit for the determination of FXI activity in concentrates of human FXI.
The FIXa formed activates FX to FXa in the presence of FVIII, thrombin, phospholipids and calcium ions. The amount of FXa generated is determined by the hydrolysis of a chromogenic substrate of FXa.
The amount of para-nitroaniline released during this hydrolysis and measured at 405 nm is proportional to the concentration of FIXa in the reaction medium.
- 10 vials of 4 mL of freeze-dried plasma
