ABSTRACT

Vesicle fluctuation analysis (VFA) is a simple experimental technique for extracting information about membrane physical properties by analyzing the conformational fluctuations of giant vesicles visible under optical microscopy. Detailed analysis of membrane conformational fluctuations reveal information about material properties of the membrane, in particular about the bending rigidity, but it has also a range of additional applications. VFA provides a unique possibility to analyze the consequences of the cooperative phenomena occurring at mesocopic length scales that are contained within the membrane fluctuations at macroscopic length by testing theoretical predictions of phenomenological models and extracting estimates of model parameters. This chapter presents the background and principles for VFA of quasi-spherical giant unilamellar vesicles (GUVs). The minimal requirements for establishing an experimental facility are discussed along with the key elements of image analysis and software for data treatment. Finally, some applications and future possibilities of VFA are given.