Thrombus formation is inhibited by argatroban (a thrombin inhibitor) and heparin in the Endo-chip laser-injury model. (A) Blood was incubated with vehicle, argatroban (0.5 μg/mL), or heparin (0.5 U/mL) for 10 minutes at RT. Blood was then labeled with annexin V, anti-CD41, and antifibrin antibody, recalcified with CaCl₂ (10 mM), and then immediately perfused through the Endo-chip at 100 s^–1, followed by laser pulse to the endothelial layer. Representative images of annexin V (red), platelet (CD41, green), and fibrin (magenta) accumulation at the injury site at 10 minutes. (B) Kinetics of annexin V (left panel), platelet (middle panel), and fibrin (right panel) over time in response to vehicle, argatroban, or heparin. (C) Annexin V (upper left panel), platelet (upper right panel), and fibrin (lower panel) AUC after treatment of blood with vehicle, argatroban, or heparin. Mean ± SD, n = 5 independent experiments, 1-way analysis of variance with Dunnett’s multiple comparisons test. AUC, area under the curve.