Bioluminescence is the production and emission of light by a living organism. It is the energy released by a chemical reaction in the form of light, which is the product of a chemical reaction. Bioluminescence is a form of luminescence, or cold light emission; less than 20% of the light generates thermal radiation. It should not be confused with fluorescence, phosphorescence or refraction of light. Ninety percent of deep-sea marine life are estimated to produce bioluminescence in one form or another. We utilize this reaction to tag different bio-activities.