Recent Developments in Super Resolution Fluorescence Microscopy

Recent developments in fluorescence microscopy techniques have broken the diffraction limit and achieved the spatial resolution of sub 100 nm range. Saturated excitation (SAX) microscopy and stimulated emission depletion (STED) microscopy utilize saturable optical phenomena seen in laser excitation and stimulate emission of fluorescence molecules to induce strongly nonlinear optical effects for the resolution improvement. Photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) applied photoswitchable fluorescence probes for precise measurement of positions of the fluorescence probes in a sample in a few tens of nanometer scale. This review introduces the principles and the characteristics of those super resolution microscopy techniques with discussing the imaging formation and the resolution limit in conventional microscopy techniques.