Figure 18.1 — Optically trapped vesicle Figure 18.1 — Optically trapped vesicle. Artistic representation of an optical tweezers holding a vesicle loaded with sucrose. The inset shows a confocal microscopy image of an optically trapped giant unilamellar vesicle (GUV) whose membrane is labeled with a red dye and whose lumen is labeled with a green dye.Reprinted with permission from Bendix and Oddershede, Nano Lett. 11, 5431–7. Copyright (2011) American Chemical Society.