Accordingly, by TEM we demonstrated that a brief stimulation with ATP (1 mM, 5–7 min) led to the formation of multiple bleb-like structures at the plasma membrane, a morphological change typically induced by ATP (Figure 2B); the identity of such structures was confirmed by SEM (Figure 2C). Moreover, the kinetics of the process was studied by live-cell imaging of CHME-5 cells transfected with a membrane-bound form of GFP (farnesyl-GFP): multiple and motile blebs appeared at the plasma membrane 2 min after the addition of ATP (Figure 2D). As MVs are expected to retain a typical set of proteins, their presence on the multiple bleb-like structures that can be observed also by conventional fluorescence microscopy was tested. Figure 2E shows that such structures were stained by FITC-conjugated phalloidin (which labels F-actin) and by antibodies against the raft-resident proteins flotillin-1 and desmoyokin-AHNAK (d/A), both found already associated to MVs (15).