A new kind of optical microscope, developed under leadership of researchers from the Institute of Nanobiology and Structural Biology GCRC of the Academy of Sciences of the Czech Republic, and from University of South Bohemia, will allow visualizing many processes inside living cells that have, until now, been impossible to observe. The new technology builds on an advanced type of an optical microscope called a two-photon microscope. In a two-photon microscope, the biological sample is being illuminated by a powerful infrared laser in a way that allows three-dimensional localization of fluorescent molecules (molecules that glow when irradiated by light of a particular wavelength). Fluorescent molecules are often used in biology for visualization of otherwise colorless biological molecules. The current improvement lies in modifying the properties of the laser beam so that the light waves alternately oscillate in various directions (different polarizations). This modification allows using a two-photon microscope not only to visualize where the fluorescent molecules are, but also how they are oriented. The researchers have shown that orientation of a fluorescent label attached to particular protein can be used to deduct information about structure of the protein molecules, in living cells and tissues. Since the structure of protein molecules often does not stay constant, but changes when a protein molecule is carrying out a particular task inside a cell, the new kind of microscope allows detecting whether a particular molecular process is taking place.
The new microscope should allow discovering new pharmaceutical drugs, by providing a new way to see whether a chemical (a potential drug) affects a particular process in a cell. Apart from uses in pharmaceutical industry, the microscope should also contribute to advancement of our understanding of how cells and organisms work. A particularly promising area of applications is visualizing electrical signals traveling in neurons of a brain. The design and applications of the new microscope have now been protected by a Czech patent, and patent protection in other countries is being sought in order to commercialize the discovery.
The published results are an outcome of 10 years of effort by the lead author of the study, initially during his stay at Columbia University in USA, and later continued by his team at the Institute of Nanobiology and Structural Biology and University of South Bohemia, in Nove Hrady and Ceske Budejovice. The first three authors of the publication carried out their work at the Academy of Sciences and University of South Bohemia, the last author is a collaborator at Columbia University. The research was financially supported by the National Institutes of Health (USA), the McKnight Foundation (USA), Columbia University (USA), the European Union, the government of the Czech Republic, the University of South Bohemia, and by personal savings of the lead researcher.
Josef Lazar, Alexey Bondar, Stepan Timr, Stuart Firestein: Two-photon polarization microscopy reveals protein structure and function, Nature Methods, 2011