ABSTRACT
In light microscopy, a beam of light is focused through a microscope using glass lenses to produce an enlarged image of the specimen. The incident light that passes through the specimen is then focused by the objective lens on to its focal plane, creating a magnified image. Standard light microscopy is the most common microscopy technique in use today and uses a compound microscope. In fluorescence microscopy, the light microscope is adapted to detect the light emitted by a fluorescent compound that is used to stain selectively components within the cell. A chemical is said to be fluorescent if it absorbs light at one wavelength and then emits light at a longer wavelength. Confocal scanning microscopy is a refinement of normal fluorescence microscopy which produces clearer images of whole cells or larger specimens. In scanning electron microscopy, a specimen is fixed and then coated with a thin layer of a heavy metal such as platinum.
