Thrombus formation in the carotid artery after FeCl₃ treatment. Experiments were carried out as described in the text. (A) The histogram shows the distribution of responses to FeCl₃ treatment. Black indicates stable thrombi; gray, unstable thrombi; and white, no thrombi. (B) Tracings for all mice tested using 2-minute 15-second exposure to FeCl₃ are shown. Similar results were found for mice exposed to FeCl₃ for 2 minutes 30 seconds. Normal flow rate is approximately 1 mL/min. A flow rate of 0 indicates complete occlusion of the artery by the thrombus.