Localization Microscopy Using GFP

Scientists at Heidelberg University, Germany have developed a new technique for localization microscopy, the “spectral precision distance microscopy” (SPDM). Using visible light, this method allows a single molecule resolution of celullar structures down to the range of few nanometer, about 20 times better than the conventional optical resolution. The researchers invented a new instrument which is a combination of the world’s fastest nano light microscope for 3D cell analysis and the new SPDM technique. Prof. Christoph Cremer of the Kirchhoff Institute of Physics and his team were able to show that SPDM can be realized by common fluorescent dyes, such as the green fluorescent protein (GFP) which can be switched on and off by means of light, as long as certain photophysical conditions are fulfilled. This can be achieved via the so-called “reversible photobleaching” of the dye. So far, only special fluorescent dyes could be used as temporally convertible light signals. According to Cremer there are millions of specimens containing gene constructs with dyes from the GFP group available in biomedical laboratories all over the world. They could be put into immediate use for this new kind of localization microscopy.
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