ABSTRACT
Fluorescence microscopy was developed in the early part of the 20th century. The transmittance of light intensity through the optical components of a microscope is critical in fluorescence microscopy, where high resolution imaging requires high magnification with minimal loss of image brightness. Light Amplification by Stimulated Emission of Radiation (Laser) represents another option for providing excitation energy for fluorescence microscopy. Pulsed lasers are finding more and more applications in fluorescence microscopy, especially in two-photon excitation microscopy and in the two- and three-dimensional measurement of fluorescent lifetimes in intact cells and tissues. Since the fluorescence microscope performs basically as a filter fluorometer, a variety of wavelength selection devices have been developed to select the wavelengths of excitation and emission. Detectors for fluorescence microscopy range from photomultiplier tubes, which are used for quantitative measurements, to imaging detectors, which allow the acquisition of two-dimensional images of fluorescence.
