Activities of 14E11. Effect of 14E11 (A) or APC (B) on the aPTT of mouse plasma. Pooled mouse plasma was supplemented with APC or 14E11 and tested in the aPTT assay as described in “Anticoagulants.” 14E11 was tested in 3 separate clotting experiments using different plasma pools from 3 or 4 mice each, and data shown are averages of clotting times ± SEM. Effect of 14E11 (C) or APC (D) in vivo. A single subcutaneous injection of 14E11 (4 mg/kg) or APC (6 mg/kg) was given to mice (n = 12 each for the 0-hour and 0.5-hour groups, n = 3 each for 2- to 72-hour groups), and blood was drawn via cardiac puncture into one-tenth volume/volume 3.2% citrate at various time points. Blood was centrifuged for platelet-poor plasma, and the aPTT was measured immediately using an Amelung KC4 coagulometer. Data are mean ± SEM.