Effect of echicetin (A) and echistatin (B) on CHO cells transfected with either vβ3 or GPIb complex. A 96-well microplate was coated with vWF. Confluent CHO cells transfected with either vβ3 (•) or GPIbβIX (▪) were detached with Versene (GIBCO) for 30 minutes at 37°C. After washing with PBS, the cells were resuspended in PBS containing 1 mmol/L CaCl₂ and MgCl₂. The concentration of the cell suspension was adjusted to 2 × 10⁵ cells/mL. Varying concentrations of echicetin and echistatin were added to 100 μL aliquots of the cell suspension 15 minutes before 2 hours of incubation on the plate. Unbound cells were gently washed away with PBS. The adhesion procedure was followed according to the legend of Fig 2.