A German and two American scientists won the 2014 Nobel Prize for Chemistry yesterday 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 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.