Martin Chalfie

Columbia University

Martin Chalfie is an American neuroscientist and biochemist, William R. Kenan Jr. Professor of Biological Sciences at Columbia University in New York City. He shared the 2008 Nobel Prize in Chemistry with Osamu Shimomura and Roger Tsien for the discovery and development of the green fluorescent protein (GFP). Chalfie's transformative contribution was demonstrating that GFP could be used as a genetically encoded fluorescent marker in living organisms—a simple but paradigm-shifting idea. In 1994, his laboratory published a landmark paper showing that the GFP gene from the jellyfish Aequorea victoria could be expressed in bacterial and nematode (C. elegans) cells, causing them to glow green under ultraviolet light, with no cofactors, substrates, or external processing required. This elegance—that a single gene encoding a protein could produce fluorescence in any living cell—immediately opened the door to fluorescently tagging any protein in any organism. GFP and its derivatives (including the many color variants developed by Roger Tsien) have revolutionized cell biology, enabling scientists to watch proteins, organelles, and cells in real time in living systems. Chalfie uses C. elegans as a model to study the development and function of mechanosensory neurons, which detect gentle touch, discovering many genes essential for this sensory modality. He has received the Gairdner Foundation International Award, the Rosenstiel Award, and is a member of the National Academy of Sciences.