Scientists Eric Betzig and William Moerner of the United States and Stefan Hell of Germany won the Nobel Prize in chemistry on Wednesday for developing new methods in optical microscopy. According to the Royal Swedish Academy of Sciences, the trio was selected for the development of super-resolved fluorescence microscopy, or ‘nanascopy’.

“Their ground-breaking work has brought optical microscopy into the nanodimension,” the academy said.

Each recipient, working independently, contributed to the development and implementation of this technique throughout living tissue. Hell studied brain synapses of nerve cells; Moerner studied proteins related to Huntington’s disease; and Betzig followed embryonic cell division.

The resolution of optical microscopy was thought to be limited by the wavelength of light, unable to surpass resolution of 0.2 micrometers. For more highly-resolved images, scientists had to rely on electron microscopy. The electron has a wavelength approximately 100,000 times shorter than the photon, allowing for greater resolution. Observing living tissue, however, is extremely difficult with electron microscopy, as a near vacuum is needed to avoid electron scattering.

The Nobel laureates managed to work their way around the limitation of optical microscopy using the principles of fluorescence. By barraging a fluorophore-tagged molecule with photons, the molecule briefly enters an intrinsically-determined excited state, resulting in the emission of photons of a specific wavelength. The specificity of the emitted photon allows scientist to filter out all other light.

Using these principles, Stefan Hell developed stimulated emission depletion (STED) microscopy in 2000. Hell’s technique uses one laser to stimulate fluorescent molecules to glow, and another to cancel out all fluorescence except for that in a nanometer-sized volume. This technique can be repeated to scan a given sample.

Eric Betzig and William Moerner independently contributed to single-molecule microscopy, another novel application of fluorescence. Scientists image an area repeatedly, only exciting a few dispersed molecules at a time. Superimposing these images yields an image resolved at the nanolevel. This technique was utilized by Betzig for the first time in 2006.

“Today, nanoscopy is used world-wide and new knowledge of greatest benefit to mankind is produced on a daily basis,” the academy said in a press release.