TIRF = Total Internal Reflection Fluorescence, or Total Internal Reflection Fluorescence, is a microscopy method using total internal reflection of an excitation beam from the interface of 2 media with different refractive indices. This method is based on the suppression of background fluorescence, where the fluorescence is deflected away from the focal plane, thereby increasing the signal-to-noise ratio and resolving the planes in the sample. The reflection of light from the interface results in the formation of a very thin electromagnetic field (called the Evanescent waves are used to excite thin layers of the sample (less than 200 nm) and to detect fluorophores in these thin layers.
