The ability to peer inside cells and observe their inner workings is crucial to modern research and medicine. Professor William Moerner’s groundbreaking work in optical microscopy, for which he was awarded the 2014 Nobel Prize in Chemistry along with two other scientists, gave researchers this capability.
While scientists had used optical microscopes, which magnify visible light, to study organisms too small to be seen by the naked eye for centuries, a fundamental law of optics, called the diffraction limit, prevented them from using the instruments to discern details within cells. The limit refers to the fact that optical imaging systems’ resolution can never be better than half the wavelength of light, in effect precluding them from providing a clear look into cells.
Professor Moerner made two breakthroughs that laid the foundation for a workaround. In 1989, he was the first to measure the light absorption of a single molecule. Later, in 1997, he discovered that the green fluorescent protein (GFP), which scientists linked to other proteins to reveal their locations when the GFP glowed, had a variant whose glow could be turned on and off by shining specific colours of light on it. This development was crucial for a subsequent imaging method that relied on fluorescing a few molecules at a time, taking images each time, and combining the images for a sharper view into cells that circumvented the diffraction limit.
The work by Professor Moerner and his fellow Nobel Laureates brought optical microscopy into the nano-dimension, and “today, nanoscopy is used worldwide and new knowledge of greatest benefit to mankind is produced on a daily basis”, the Nobel Prize committee said.
Professor Moerner has studied proteins related to Huntington’s disease and is investigating the glycocalyx, a dense layer of sugars, proteins and lipids that covers nearly all cells in the human body and is involved in various cellular processes and diseases, including cancer. He is also researching ways to better combine optical and electron microscopy to improve imaging.
He is currently Harry S. Mosher Professor of Chemistry at Stanford University, and a fellow of the Optical Society of America, American Physical Society, and other organisations. He has also won the Wu Zheng Kai Chemistry Prize, Peter Debye Award in Physical Chemistry, Wolf Prize in Chemistry, and other awards.