The widefield microscope is named because of the large areas of information that are recovered along the axial axis of the sample. It is also known as the epifluorescence microscope due to the position of the light source relative to the sample. Its light source is an arc lamp that emits highly energetic white light. To obtain monochromatic light, polarizing filters are used to select wavelengths that are useful for selectively irradiating fluorochromes present in a sample. The advent of the synthesis and introduction of fluorochromes for microscopic observation was no trivial matter; for this reason their creator, Osamu Shimomura, was awarded the Nobel Prize in Chemistry in 2008. Fluorochromes have an active site, the fluorophore, which is a sequence of amino acids that produce fluorescence after being irradiated with energy absorbed by the fluorochrome. All fluorophores, in turn, have a site that determines the color of the emitted light, the chromophore. The radiation-emission cycle of a fluorochrome will depend on its ability to continuously absorb and release energy before the extinction of fluorescence emission occurs.