The resolution of light microscopy is limited by diffraction to approximately half the wavelength of light (i.e., about 250 nm). Objects smaller than this cannot be resolved from one another using conventional light microscope techniques. The example below shows how adjacent objects smaller than the diffraction limit can be resolved using Single Molecule Localisation Microscopy (SMLM).
Panel A shows a light microscope image of fluorescently labelled DNA origami structures immobilized on glass. Each structure appears as a bright dot.
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