Osamu Shimomura (born 1928), a Japanese citizen, was responsible in 1962 for isolating GFP from the jellyfish Aequorea victoria and discovering "that this protein glowed bright green under ultraviolet light."
The discovery of GFP has meant that "researchers have developed ways to watch processes that were previously invisible, such as the development of nerve cells in the brain or how cancer cells spread," according to the Academy.
Martin Chalfie (born 1947) and Roger Y Tsien (born 1952) have been rewarded for their roles in developing the scientific application of the discovery.
Chalfie, a professor at New York's Columbia University, "demonstrated the value of GFP as a luminous genetic tag for various biological phenomena".
Tsien, a professor at the University of California, "contributed to our general understanding of how GFP fluoresces. He also extended the colour palette beyond green allowing researchers to give various proteins and cells different colours."
Osamu Shimomura is Professor Emeritus at Marine Biological Laboratory, Massachusetts, and Boston University Medical School.
The Prize money of 10 million kronor ($1.38 million) is to be shared equally between the three Nobel Laureates.