Fig. 2. Videomicroscopy images of platelet-rich plasma samples during flow in parallel flow plate microchambers. (  A ) Recalcified, sparged sample without surfactant added. (  B ) Recalcified, sparged sample with surfactant Pluronic F-127 added. (  C ) Citrated (not recalcified), sparged sample without surfactant added.  Arrows indicate presence of microbubbles.