The GFP gene is a gene from the jellyfish Aequorea victoria that encodes a green fluorescent protein. GFP was isolated from the jellyfish in 1994 and is now a commonly used biological marker in genetic engineering experiments.
The gene for GFP has been genetically implanted into a number of different animals, including bacteria, rabbits, mice and even human cells. When GFP is used in combination with other genetic manipulation, the presence of the protein provides a simple method to check for the presence of certain genes. GFP has also been mutated in the laboratory to create strains that fluoresce at different wavelengths, including yellow, blue and cyan.