Factor XI Deficient Plasma – large

Deficient plasma for the assay of FXI. All the clotting factors are present (constant and in the normal range, brought by the deficient plasma), except for FXI, which is brought by the diluted tested plasma, and clotting is triggered with cephalin, activator and calcium (APTT). FXI is the limiting factor and clotting time is inversely proportional to the concentration of FXI.