single molecule fluorescence spectroscopy
SMD, single molecule detection, single-particle tracking, SPT, PALM microscopy, single-molecule imaging, single-molecule localization microscopy, SMLM
Single molecule fluorescence spectroscopy is a method of physical chemistry in which individual molecules can be made visible. Thus the dynamics and interactions in cellular systems can be examined. The technique has developed rapidly in recent years, especially in the area of high-throughput single molecule detection. In biomolecular analysis, the method enables the identification of subpopulations and the localization of molecules with sub-wavelength precision. The technology is used in biological, clinical and medical research to follow the movement of individual molecules in living cells, e.g. for ultra-sensitive and specific DNA sequencing or for the detection of diseases.
During the process, the sample is brought under a special light microscope, which is optimized for the extremely small detection volume, and then excited by means of a laser. The photons emitted during the resulting fluorescence triggered can be tracked over longer periods of times with the aid of a microscope (single-particle tracking, SPT) or may also be put underneath a time-correlating single photon measurement.