Stephan Sigrist is professor for biology at the Freie Universität Berlin in Germany. His research focus are synapses, synaptic information transfer and processing between neurons in the developing drosophila larva. His aim is to understand how synapses actually get diversified in our brains. Synapses are very small. Their diameter is about 200 nm. Traditionally electron microscopy is used for the investigation of these structures. "With the development of super-resolution light microscopy we're getting a tool at hand which is simple in application and often allows us to use the very same antibodies which we use for standard immunofluorescence stainings. It brings us exactly in the size domain where we want to ask our questions." STED microscopy helped Sigrist to understand the distribution of a gene called "Bruchpilot" within the protein architecture of the synapses and why it plays such a big role for the information processing at synapses. Major challenges in STED microscopy for Sigrist are optics for further improvement in resolution, the development of probes suitable for super-resolution and applying STED to living, intact organisms. However, he has the impression that with the possibility of gated STED working on the functional molecule of the synapse in a live fashion becomes more and more a reality, especially as bleaching is a major obstacle. For Sigrist super-resolution microscopy is very significant for the study of proximity relations of proteins in a size range of only a couple of nanometers. "I'm not saying that super-resolution light microscopy is going to make biochemistry superfluous, but I'm saying, that we will able to read out protein relations to a degree, which was in former times, really the domain of only biochemical access."Being one of the first users of a Leica STED microscope, Sigrist is happy about the good relations he always had with Leica Microsystems, especially as one of his former students now is an application specialist at Leica Microsystems. "That's a very intense, very fair, very sort of like academic style exchange, which is good for all sides."