Fluorescence imaging is often used in a light microscopy setting and revolved around the use of either autofluorescent properties of the sample or fluorescent marker molecules. Hereby, specific wavelengths of an excitation source (lamp, LED or laser) are absorbed and re-emitted at longer wavelengths, enabling a separation the incoming and emitted light and thus ensuring a high contrast. Fluorescent markers, also called fluorophores, can be attached to a large variety of target structures with high specificity, for example through the use of antibodies. This allows researchers to study the precise topology of otherwise invisible structures, detect the presence or absence of certain molecules, visualize dynamic processes in living tissue in real time and more.
Fluorescent imaging forms the basis for numerous super-resolution microscopy techniques which break the resolution imposed by the diffraction barrier. Popular examples are Stimulated Emission Depletion (STED), Stochastic Optical Reconstruction Microscopy (STORM), Photo Activated Localization Microscopy (PALM).