Scientific American has an interesting Q&A with Dr. Martin Chalfie (Columbia University), who earlier this month received a one-third share of the 2008 Nobel Prize in Chemistry for his research on green fluorescent protein (GFP). The other co-winners of the chemistry prize are Osamu Shimomura (Marine Biological Laboratory, Woods Hole) and Roger Tsien (University of California, San Diego).
What makes GFP so special? Found naturally in jellyfish, it has the remarkable property of producing green light when exposed to blue and ultraviolet light. In other words, if you shine "invisible" ultraviolet light on GFP, it glows green. Chalfie's idea was to use GFP as a molecular beacon. He used molecular biology techniques to genetically "tag" a specific protein in the cell with GFP. The protein, with its GFP beacon attached, can then be easily followed inside of a living cell with a simple light microscope. This trick has revolutionized the way that cell biologists and biochemists examine living systems. A more detailed discussion of how GFP works can be found on the Nobel Prize website (download PDF here).
Interestingly, the man widely accepted as having set the scientific stage for the Nobel Prize-winning work, Dr. Douglas Prasher, was not included in the award. The New York Times recently ran a story about Dr. Prasher, who is unfortunately no longer in science.