Wide-field fluorescence microscopy

light path for a wide field fluorescence microscopeWide-field fluorescence microscopy is a very widely used technique to obtain both topographical and dynamic information. It relies on the simultaneous illumination of the whole sample. The source of light is usually a mercury lamp, giving out pure white light. Optical filters are then used in order to select the wavelength of excitation light (the excitation filter). Excitation light is directed to the sample via a dichroic mirror (ie a mirror that reflects some wavelengths but is transparent to others) and fluorescent light detected by a camera (usually a CCD camera). Thus both the illumination and detection of light covering the whole visual field of the chosen microscope objective is achieved simultaneously.