Figure 18.3 — Vesicle membrane manipulation by optical tweezers Figure 18.3 — Vesicle membrane manipulation by optical tweezers. (a) A 1 μm-diameter vesicle with aqueous core held in optical tweezers is deformed at high power. The shape of the vesicle is revealed by the distribution of fluorescence from dyes contained in the vesicle interior (upper panels) and membrane (lower panels). (b) A part of the membrane of a giant flaccid vesicle (which extends beyond the region of the image) is pulled by optical tweezers applied at the point indicated by the arrow. (c) A line tweezers, whose location is shown by the dotted line in frame (i), is used to manipulate a vesicle. In frames (ii), (iii), (iv) and (v), the vesicle can be seen to undergo a budding transition as a result of the laser-induced surface tension. In frame (vi), two separate vesicles are visible.Figure (a) is reprinted from Bendix and Oddershede, Nano Lett. 11, 5431–7. Copyright (2011) American Chemical Society.Figure (b) reprinted from Bar-Ziv et al., Biophys. J. 75, 294–320, copyright (1998), with permission from Elsevier.Figure (c) is reprinted from Spyratou et al. (2009), Colloids Surf. A 349, 35–42, copyright (2009), with permission from Elsevier.