SNAP23 mice show defective hemostasis and arterial and venous thrombosis. (A) Mice anesthetized with a ketamine/xylazine mix had 5 mm of tail tip resected before immediate immersion in 37°C saline. Tail bleeding was followed to the 10-minute experimental end point. N = 5. (B) Mice were infused 0.1 µg/g body weight Dylight-488–conjugated anti-GPIbβ antibody prior to induction of thrombus formation. Thrombus progression was followed for 10 minutes by time-lapse fluorescence microscopy, and representative images of WT (n = 12) and KO (n = 6) of thrombus formation taken under a 4× objective are shown (i) and mean fluorescence intensity for the thrombus is plotted against time after initiation of thrombosis (ii). Data were analyzed by 2-way ANOVA. (C) Mice had their IVCs exposed surgically, and thrombosis was induced by means of a ligature for 48 hours. (i) Representative images are shown of excised vena cavae showing extent of thrombus formation (scale bar = 1 mm). (ii) Thrombus length was recorded after harvest from WT (n = 4) and KO (n = 3) mice. Data were analyzed by Mann-Whitney U test. *P < .05. (iii) Immunohistochemistry was carried out to stain leukocyte marker CD45 (red), platelet marker CD41 (green), and DNA (blue) on venous thrombotic sections, with representative images from WT and KO mice (scale bar = 500 µm).