Clotting of CTI-inhibited fresh blood triggered with LPS-THP-1. CTI-inhibited whole blood was triggered to clot by varying concentrations of LPS-THP-1 (▴, n = 5 blood donors). A total of 2 × 10⁴ LPS-THP-1 cells/mL are shown to have equivalent clotting activity to the 5pM rTf). Clot time represented by the horizontal dashed line (n = 5). An experiment using another population of titrated LPS-THP-1 cells illustrates a very similar titration curve indicating reproducibility of LPS-THP-1 activity (open gray box, n = 1 donor). A total of 5 × 10⁴ nonstimulated THP1 cells/mL (■, n = 5 donor) is equivalent in clotting activity to 2.5 × 10³ stimulated THP1 cells/mL. Nonstimulated THP1 cells show 5% of stimulated THP1 activity.