Contact

Prof. Dr. Stefan W. Hell

NanoBiophotonics Dept.
Max Planck Institute for Biophysical Chemistry, Göttingen
Phone:+49 551 201-2500Fax:+49 551 201-2505

Further Information

STED - Insights into the nanoworld, a film about Stefan Hell and his work.

Quantum Physics

The realm of lasers, lenses and mirrors

Hell explains his decision with the comment, “Compared with all the other institutions, it was clear to me at that time that I would be able to work here best of all.” It was the Harnack principle that tipped the balance: in addition to a generous budget, an appointment as Director carries with it the maximum possible freedom to research precisely what interests them.

The resolution limit according to Hell: The physicist added the root term to the denominator of Abbe's formula. ThusΔx, the distance between the two just-distinguishable points, decreases as the intenxsity I of the laser that stimulates the emission of the excited fluorescence molecules rises. Zoom Image
The resolution limit according to Hell: The physicist added the root term to the denominator of Abbe's formula. ThusΔx, the distance between the two just-distinguishable points, decreases as the intenxsity I of the laser that stimulates the emission of the excited fluorescence molecules rises. [less]

And that is what Stefan Hell proceeded to do. For his visionary highresolution project, he needed more than just physicists who could deal with optics and design laser systems. He also established a chemistry and molecular biology group whose work involves developing suitable fluorescent markers that can easily be switched on and off, and a biology group that investigates applications in the life sciences. The combination works well, Hell believes.

The staff works diligently in the laboratories and, it would seem, with a sense of commitment. The labs are named the Gauss Room, Debye Room and Born Room, after famous scientists who once worked in Göttingen. Here, behind the high-security doors, is a world of lasers, lenses and mirrors, dozens of them mounted on bare optical tables. Some of the microscopes are the commercial versions – built by a division of the old company that Hell worked for when he was working on his doctorate. The company has since been bought out by Leica, and now employs some of Hell’s graduates.

This is where the various procedures are optimized. Researchers are improving the temporal resolution in order to be able to depict processes in living cells. Others are working on new fluorescence molecules that can be switched at will, and dock with certain cell structures. New areas of application are also being developed – for example in materials research. New combinations of STED and 4Pi microscopy are being explored, and new fluorescence switching mechanisms created.

However, Stefan Hell wouldn’t be Stefan Hell if he simply stuck to the beaten track. “Of course we are exploring the potential of these microscopes,” he explains. In theory, there should be little or no limit to the minute dimensions they offer access to. “And that would mean that we ought to be able to see not just individual molecules, but potentially even what’s inside them,” says Hell, once again with a daring look in his eye.

Did he ever doubt that his idea would prove successful? Serious doubts – no. Even if the initial groundbreaking experiments are complex and require expensive new equipment, in Hell’s view, that’s no reason to shy away. After all, technology is developing all the time. “Envy and criticism are very important, too, because they provide added incentive, as well as highlighting the points that require attention. If an idea is powerful enough, nothing can stop it. And the idea that light microscopy was possible beyond the Abbe limit was very powerful.”

 
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