A chromogenic kit
FIX is activated by human FXIa with concomitant activation of human FX by generated FIXa in the presence of FVIII, calcium ions and phospholipids. The amount of formed FXa is related to the FIX activity and is measured through hydrolysis of a chromogenic FXa substrate. There is no use of FIX deficiency plasma. The Kit contains a fibrin polymerization inhibitor and a heparin antagonist.