Super-resolution imaging in live cells

Over the last twenty years super-resolution fluorescence microscopy has gone from proof-of-concept experiments to commercial systems being available in many labs, improving the resolution achievable by up to a factor of 10 or more. There are three major approaches to super-resolution, stimulated emission depletion microscopy, structured illumination microscopy, and localisation microscopy, which have all produced stunning images of cellular structures. A major current challenge is optimising performance of each technique so that the same sort of data can be routinely taken in live cells. There are several major challenges, particularly phototoxicity and the speed with which images of whole cells, or groups of cells, can be acquired. In this review we discuss the various approaches which can be successfully used in live cells, the tradeoffs in resolution, speed, and ease of implementation which one must make for each approach, and the quality of results that one might expect from each technique.