The first time I heard about FRET during a journal club, my guitarist brain automatically thought about the raised element found on the neck of my guitar...not really useful for a biologist you would say. The student was of course talking about the now well-known FRET, aka Fluorescence (Förster) Resonance Energy Transfer, technique which allows the detection of molecules' interactions, modifications or dissociations in situ. Used since the mid-90s, this technique has revolutionised the way we apprehend molecular complexes and is still a very useful tool.
Like a guitar hero (that I’m not), FRET loves playing “live”. Indeed, FRET was one of the first techniques which enabled the measurement of single molecule interactions in living cells using a microscope. Historically, molecular interactions were detected by indirect means often using probes with the potential to target several molecules. By analogy, it was like pointing out a group of students in a university hall but not knowing if these students know or interact with each other. FRET reduced the scale of our perception about molecular interactions.