ABSTRACT
In this chapter, we rst discuss the diffraction limit and its appearance as a PSF; then, the STED process in a single molecule energy level, as well as its behavior in a uorescent medium. The combination of other techniques with STED, such as time-gating, iso-STED, STED and 4Pi, twophoton excitation, and self-aligned STED techniques are discussed. Next, the technical notes on the experimental instrumentation of STED are presented. Finally, the applications of STED to a variety of biological specimens are listed.
