A novel microtiter plate assay for the quantitation of procoagulant activity on adherent monocytes, macrophage and endothelial cells.

The interaction of monocytes, macrophages and endothelial cells with inflammatory agents induces cell surface changes resulting in the activation of the coagulation cascade. A large volume 96 well plate microtiter assay has been developed which permits the quantitation of procoagulant activity on endotoxin stimulated cells without requiring the use of purified coagulation factors. Procoagulant activity is measured through a two stage amidolytic assay using commercially available Proplex as a source of factors VII and X and the chromogenic substrate S2222. The assay is rapid, linear, and sensitive as procoagulant activity can be detected on as few as 5 X 10(3) monocytes or macrophages and 3 X 10(2) endothelial cells.