Ex vivo perfusion studies. Blood from 5 to 8 mice was pooled to perform each experiment. Representative images show platelet adhesion in WT mice (panels A and D), Gp6^−/−SHORT mice (panels B and E), or Gp6^−/− LONG mice (panels C and F) to insoluble, fibrillar Type I collagen (panels A-C) or mouse fibroblast matrix (panels D-F). These results are representative of more than 4 experiments using genetically similar mice. The bar in the bottom right corner of each panel indicates distance, such that the magnification in panels B and C is twice that of the remaining panels.