BRIGHT LIGHT, BETTER LABELS

摘要

Scientists love to decorate their favourite biomolecules with fluorescent tags. Attaching light-emitting labels to a protein can reveal when and where in a cell it functions, but usually the details are fuzzy. Optical microscopes use light with wavelengths between 350 and 750 nanometres, and structures smaller than about 200 nm cannot be seen clearly. That is much bigger than the thickness of a cell membrane and is about half as long as the mitochondria that supply cells' energy.