With the discovery of the STED Microscope, Physicist Prof. Stefan W. Hell, Director at the Max Planck Institute Biophysical Chemistry in Göttingen was one of this year's three finalists in the "Life's Work" category of Europe's most important innovation award, the "European Inventor of the Year 2008". Read how live videos can be "filmed" from the inside of a cell in the future with this key technology, which opens up completely new areas of application in bio-technology and medicine.

The discovery of the STED Microscope was awarded highest priority from among more than 250 projects in an EU innovation competition back in 2004. In 2006 the inventor Stefan Hell received the "Innovation Award of the German Federal President", and this year he was one of the three finalists in the "Life's Work" category of Europe's highest innovation accolade, the "European Inventor of the Year 2008 Award". The award honors inventors and their inventions both in and outside Europe that, "have made an important contribution to technological progress and therefore to Europe's economic strength." The prize was set up by the European Commission and the European Parliament and is decided by an independent international jury.

1000 times thinner than a hair
Until now microscopy with focused visible light had always been subject to the old diffraction limits determined by Abbe. Since the invention of microscopy by Ernst Abbe in the 17th century, it was considered incontrovertible that light microscopy could ever make things that are less than a half a wavelength apart visible. Using blue light this would correspond with a maximum resolution of approx. 200 nanometers. The Department of NanoBiophotonics at the Göttingen MPI (Max Planck Institute) however, has now shown that diffraction limits can be removed in fluorescent microscopy, which is eminently important in biology. The first example of this was STED (Stimulated Emission Depletion) microscopy, which currently delivers resolutions of 50 mm and just recently could even resolve 16 mm at experimental level, which represents structures that are 1000 times thinner than a human hair.

STED - this is how it works
The process is made possible by improving the established fluorescence microscopy, with which a laser beam "excites" coloring molecules in the light emission sample. STED technology works here with a second laser beam that hits the sample directly after the first light flash. This second beam displaces the excited coloring molecules again in the their resting state (depletion), even before they have started to transmit fluorescent light. If you now place the second laser beam ring-shaped around the first exciter laser, only a few molecules will begin to light in the laser spot. The controlled activation and removal on the edge of the laser beam neutralizes the fluorescent effect and the reset remains dark. The resolution of the pointwise surface scanning increases significantly. The coordination of the two lasers determines the size of the center point here, and therefore the resolution.

STED is a variant of a basic concept that removes the diffraction limits by using optical transitions between two states of a fluorescent marker. Despite diffraction, molecular resolutions can therefore be achieved with visible light and normal lenses. The research into the potential of this concept was a central component of the work of Stefan W. Hell. STED is considered a key technology that will open up new application areas in bio-technology and medicine.

Live from the cell!
STED technology could previously only be used in examining dead cells. Transmission of the examination of living cells is now also possible. With the name "Nanolive", live cell STED microscopy is to be a reality within the next three years. Both new microscopy and new fluorescent colorings and fluorescent proteins as markers are required here. In addition to still images, "videos" from living cells will also be possible to visualize dynamic processes within or between individual cells. Just recently Stefan Hell's group filmed the first live video from inside a living nerve cell with 65-nanometer resolution with a STED Microscope. This made the first ever real-time insights into the processes of signal transfer between nerve cells possible.


About the "European Inventor of the Year"
The "European Inventor of the Year" innovation award honors inventors and their inventions both in and outside Europe that, "have made an important contribution to technological progress and therefore to Europe's economic strength." The prize was set up by the European Commission and the European Parliament and is decided by an independent international jury. This year's presentation was made on 6 May 2008 as part of the European Patent Forum in Ljubljana, Slovenia. The award was presented by the Slovenian President, Danilo Türk, and the President of the European Patent Office, Alison Brimelow.

About Prof. Stefan W. Hell
Prof. Stefan W. Hell, born 1962, studied physics in Heidelberg. After attaining his doctoral degree in Heidelberg in 1990, he initially pursued his ideas as a "freelance inventor", until he returned to pursue his scientific career with his post-doctorate at the Heidelberg European Molecular Biology Laboratory (EMBL). As Head of the Laser Microscopy Group of the University of Turku in Finland he developed the basic principle of STED microscopy, which he further developed as the "new blood" group leader, and from 2002 as Director at the Max Planck Institute for Biophysical Chemistry. He is also the Head of the Department of NanoBiophotonics at the Institute. Stefan Hell is a Scientific Member of the Max Planck Society and Honorary Professor for Experimental Physics at the Georg-August University in Göttingen. He has received numerous prizes and awards throughout his career, including the "International Commission for Optics (ICO) Award" (2000), the "Helmholtz Award (2002)", the "German Zukunftspreis des Bundespräsidenten" (German President's Future Prize - 2006) and the Gottfried-Wilhelm Leibniz Award (2008).

Contact
Prof. Dr. Stefan W. Hell,
Max-Planck-Institut für biophysikalische Chemie,
Tel +49 551 201-2500, -2503
Fax +49 551 201-2505
E-mail: shell@gwdg.de