University of Marburg tests nanometer resolution light microscopes for Leica

19 March 2011

The University of Marburg is expanding its cooperation with Leica Microsystems to test a new generation of light microscopes with a resolution at the nanometer scale.

The University's Institute of Cytobiology is currently one of four institutes in the world testing a microscope with a resolution well below the diffraction limit (nanoscope).

The new technology, for which Leica Microsystems has been granted an exclusive licence, is being tested until September in the Imaging Core Facility of the special Cell Biology Research Department in Marburg.

“With this new optical nanoscopy called GSDIM (ground state depletion microscopy followed by individual molecule return), resolutions down to 25 nanometers can be achieved. This makes it possible to image sub-cellular structures or protein complexes far beyond the resolving powers of a light microscope,” says cell biologist Prof Dr Ralf Jacob of Philipps University, Marburg.

GSDIM gives true-to-detail imaging of the spatial arrangement of proteins and other biomolecules in cells and observing molecular processes by giving resolutions beyond the diffraction limit. The more insight science gains into these basic processes of life, the better it can find the causes of previously incurable diseases and develop suitable therapies.

One of the strengths of GSDIM is that it uses conventional fluorescence markers to image proteins or other biomolecules within the cells with sharpness down to a few nanometers. This includes fluorophores which are routinely used in biomedicine.

With GSDIM, the fluorescent molecules in the specimen are almost completely switched off using laser light. However, individual molecules spontaneously return to the fluorescent state, while their neighbours remain non-illuminating.

In this way, the signals of individual molecules can be acquired sequentially using a highly sensitive camera system and their spatial position in the specimen can be measured and stored. An extremely high-resolution image can then be created from the position of many thousands of molecules.

This enables cell components that are situated very close to one another and cannot be resolved using conventional widefield fluorescence microscopy to be spatially separated and sharply reproduced in an image.

“With this new widefield microscope system we are extending our super-resolution portfolio and allow even more scientists to benefit from our innovative technology and advance their research,” said Anja Schué from Leica Microsystems.