Electron microscopy only captures a static image of a cell. What is the cell doing? What is the true sequence of events in a cellular process? We can make flip books from our micrographs that tell a story, but their arrangement can be influenced by the story we want to tell. With the advent of optogenetic tools a flash of light can trigger dynamic cellular events such as neurotransmission. By coupling a flash of light with rapid high-pressure freezing, regulated vesicle fusion and subsequent vesicle recycling at synapses can be visualized (Fig. 1 above).
In this webinar, we will give a brief background on optogenetics and sample preparation for electron microscopy. We will then discuss the development of the ‘flash-and-freeze’ fixation method and potential applications of the technique.