High shear–dependent platelet disintegration. Whole blood from transgenic mice was perfused into human VWF-coated microchannels at a rate of 1800 s⁻¹. The shear rate was increased to 40 000 s⁻¹, and platelet adhesion was monitored for up to 3 minutes. Single frame images were captured at the time points indicated. hGPIbα^WT platelets progressively adopted a spherical morphology while maintaining rolling adhesion. In contrast, those hGPIbα^FW platelets still able to maintain their adhesion were observed to progressively lose their normal structure, becoming highly vesiculated followed by complete disintegration (also shown in supplemental Video 3). Scale bar represents 5 μm.