TF activity in human thrombi.

Procoagulant activity was measured in a 2-stage clotting assay. Human thrombi obtained from thrombectomy were homogenized, preincubated with FVIIa and FX for 3 minutes in presence or absence of the murine monoclonal anti-human TF antibody (HTF1-7B8). Then, human plasma containing a phospholipid mix (PC/PS = 70/30) was added and the clotting assay started by addition of Ca⁺⁺. The amount of TF was calculated from a standard curve obtained using relipidated full-length TF.