DNA origami nanorulers and emerging reference structures

The DNA origami technique itself is considered a milestone of DNA nanotechnology and DNA origami nanorulers represent the first widespread application of this technique. DNA origami nanorulers are used to demonstrate the capabilities of techniques and are valuable training samples. They have meanwhile been developed for a multitude of microscopy methods including optical microscopy, atomic force microscopy, and electron microscopy, and their unique properties are further exploited to develop point-light sources, brightness references, nanophotonic test structures, and alignment tools for correlative microscopy. In this perspective, we provide an overview of the basics of DNA origami nanorulers and their increasing applications in fields of optical and especially super-resolution fluorescence microscopy. In addition, emerging applications of reference structures based on DNA origami are discussed together with recent developments.