Epi-Fluorescence, or Reflected Light Fluorescence is a technique in which light in a certain band of wavelengths is allowed to strike the specimen. The specimen then absorbs this light energy and emits light of a longer wavelength. Specimens may be autofluorescent or may be stained with a special fluorochrome. Epi-Fluorescence was made possible with the development of the dichroic mirror which reflects certain wavelengths while allowing higher wavelengths to pass through. A complete fluorescence filter cube will contain an excitation filter, a dichroic mirror, and a barrier filter. Some filter sets are very common such as those for FITC (blue excitation) and TRITC (green excitation), and most of the fluorescence microscopes we have in stock have these cubes. As a dealer for Chroma Technology, we can supply filter sets for just about any fluorescence application. For more information on fluorescence and custom filter sets see Chroma’s website. Epi-Fluorescence is often combined with Transmitted Light Brightfield, Phase Contrast, and/ or Differential Interference Contrast.