The latest incarnation of the modern fluorescence microscope has led to a paradigm shift. This wave is about breaking the diffraction limit first proposed in 1873 by Ernst Abbe. The implications of this development are profound. So-called superresolution microscopy allows for the visualization of cellular samples with a resolution similar to that of an electron microscope, yet it retains the advantages of an optical fluorescence microscope. This means it is possible to uniquely visualize desired molecular species in a cellular environment – even in three dimensions and now in live cells – at a scale comparable to the spatial dimensions of the molecules under investigation.