(From top) Eric Betzig, William Moerner and Stefan Hell

Stockholm/London, Oct. 8 (Reuters): A German and two American scientists won the 2014 Nobel Prize for Chemistry today for smashing the size barrier in optical microscopes, allowing researchers to see individual molecules inside living cells.

US citizens Eric Betzig and William Moerner and Germany’s Stefan Hell won the prize for using fluorescence to take microscopes to a new level, making it possible to study things like the creation of synapses between brain cells in real time.

“Due to their achievements the optical microscope can now peer into the nanoworld,” the Royal Swedish Academy of Sciences said as it awarded the 8 million crown ($1.1 million) prize.

Scientists, who have been looking down microscopes since the 17th century, had long thought there was a limit to what could be seen. In 1873, Ernst Abbe stipulated that resolution could never be better than 0.2 micrometres, or around 500 times smaller than the width of a human hair.

But the three Nobel winners bypassed this limit by tagging objects with fluorescent markers and scanning them to build up a far more detailed images. Today, such “nanoscopy” is used widely to visualise the internal molecular machinery of cells.

“This is very, very important to understanding how the cell works and understanding what goes wrong if the cell is diseased,” Hell told a news conference by telephone after learning of the award.

Modern nanoscale microscopes can follow protein interactions involved in diseases like Alzheimer’s, Parkinson’s and cancer, or watch the transcription and translation of DNA to make proteins, or track the development of fertilised eggs as they divide and become embryos.

The previous limit meant optical microscopes could see objects about the size of the smallest bacteria, but not the detailed workings of individual components inside cells.

Light is a common theme of both this award and the Nobel Prize for Physics, which was given yesterday for advances in low-energy light-emitting diodes.

“It’s no exaggeration to say that super-resolution fluorescence microscopy has revolutionised imaging, so this year’s Nobel Prize for Chemistry is very well deserved,” said Stefanie Reichelt, head of light microscopy at the Cancer Research UK Cambridge Institute, University of Cambridge.

Other techniques, such as electron microscopes, can provide greater resolution but require preparatory measures that kill cells, making them of no use for observing living processes.

“If you want to see living things, you must use something which does not destroy the sample, by using normal light,” Anders Hagfeldt, a member of the Swedish academy and professor of physical chemistry at Uppsala University said.”It was said it could not be done, basically. Now, with these three laureates here, it is possible.”