Osamu Shimomura — Japanese chemist and co-discoverer of GFP

Discovery and scientific contribution

In the 1960s and 1970s Shimomura studied jellyfish of the species Aequorea victoria and purified a series of light-producing proteins. He first isolated aequorin and later the independent fluorescent protein now called green fluorescent protein (GFP). By determining its light-emitting properties and chemical behavior, he provided a tool that could be adapted as a genetically encoded marker for living cells.

Applications and impact

The availability of GFP and engineered derivatives enabled researchers to visualize proteins, cells, and developmental processes in real time without destroying samples. Major uses include:

• Fluorescent tagging of proteins to follow cellular localization and movement
• Live-cell imaging of neural activity, gene expression, and developmental events
• Creation of biosensors and fluorescent reporters for chemistry and physiology

Shimomura's foundational work made these methods possible; later improvements by other scientists expanded color variants and brightness, which broadened experimental applications across biology and medicine.

Awards, collaborators and legacy

For the discovery and development of GFP, Shimomura shared the 2008 Nobel Prize in Chemistry with Martin Chalfie and Roger Tsien. His career illustrates how careful chemical purification and curiosity about marine organisms can lead to tools with enormous practical impact. He continued to be associated with the Marine Biological Laboratory as Professor Emeritus and influenced many researchers through both publications and mentorship.

Shimomura died in Nagasaki on October 19, 2018, leaving a legacy in which a simple fluorescent protein became indispensable to modern life sciences and biotechnology.