Total internal reflection fluorescence microscope

A total internal reflection fluorescence microscope (TIRFM) is a type of microscope with which a thin region of a specimen, usually less than 200 nanometers can be observed. TIRFM is an imaging modality which uses the excitation of fluorescent cells in a thin optical specimen section that is supported on a glass slide.

Source: Wikipedia — Total internal reflection fluorescence microscope (CC BY-SA 4.0)