A worldwide study involving 20 laboratories has established and standardized a method to measure exact distances within individual biomolecules, down to the scale of one-millionth of the width of a human hair. The new method represents a major improvement of a technology called single-molecule FRET (Förster Resonance Energy Transfer), in which the movement and interaction of fluorescently labeled molecules can be monitored in real time even in living cells. So far, the technology has mainly been used to report changes in relative distances—for instance, whether the molecules moved closer together or farther apart. Prof. Dr. Thorsten Hugel of the Institute of Physical Chemistry and the BIOSS Centre for Biological Signalling Studies is one of the lead scientists of the study, which was recently published in Nature Methods.