In vivo thrombosis. Thrombosis in a carotid artery occlusion model is presented. After damage via FeCl₃ to an exposed carotid artery, blood flow in an anesthetized animal was followed for approximately 40 minutes. hTg^WT animals display a rapid and stable reduction in blood flow initiated approximately 5 minutes after chemical damage (top graph). Three representative tracings are shown but are indicative of results obtained from 10 different animals. In contrast, hTg^G233V mice were unable to occlude the carotid artery as evidenced by only small changes in the blood flow during the 40-minute experiment (bottom graph). Again, only 3 representative tracings are shown, but similar results were obtained with all hTg^G233V animals tested (n = 10). The patent carotid artery of hTg^G233V animals is in stark contrast to the occlusive thrombi that form with hTg^WT animals.