Green fluorescent protein (GFP).

The green fluorescent protein (GFP) is a type of protein with bioluminescent qualities found in the Aequorea victoria jellyfish. Bioluminescence is form of light triggered by biochemical reactions emitted by living creatures. In the case of A. victoria, which is also known as the crystal jellyfish, a blue light is emitted by a chemical called aequorin. GFP converts this light into a green color. Solutions containing GFP appear yellow under laboratory lights, but turn green again when viewed in natural light.E. coli expressing fluorescent proteins.Erin Rod [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)] Aequorea victoria, a jellyfish exhibiting luminescence due to GFP.incidencematrix [CC BY 2.0 (https://creativecommons.org/licenses/by/2.0)]