Rapid platelet aggregation on RBC-derived material visualized by brightfield intravital microscopy and SEM. (A-F) The elapsed time from the initial frame (A) is as indicated (seconds). (A) Platelets were observed binding to a group of RBC fragments (arrows). (B-F) Rapid platelet aggregation results in the formation of a large platelet complex. (G-I) Continued platelet aggregation following FeCl₃ application was visualized by SEM. The time course after FeCl₃ application is indicated in the panels.