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A special process of light microscopy makes biological structures visible up to DNA
Today, Thursday, the Meyenburg Prize 2011, endowed with 50,000 euros, will be awarded at the German Cancer Research Center (DKFZ) in Heidelberg. The physicist Professor Stefan Hell, specialist for optically high-resolution microscopy at the DKFZ, received an award for the development of a new method of light microscopy that enables living cells to be observed down to the nanomolecular level.
As announced by the German Cancer Research Center in Heidelberg, Professor Stefan Hell is honored for his outstanding developments with the 2011 Meyenburg Prize. With the help of the completely new method developed by Prof. Hell when using light microscopy, not only living cells down to the nanomolecular level but also DNA strands can be observed directly. Until now, the highest structures that were at least 200 nanometers in size could be observed with light microscopy. The new method enables biological structures that are only 20 to 50 nanometers in size to be recognized.
Limits of light microscopy broken So far, it was assumed that due to the so-called Abbe law of 1873, light microscopy can only recognize structures and objects in which two points are at least half the wavelength of the visible light apart. In other words, the natural limit of light microscopy was around 200 nanometers. Bit by bit, Heidelberg researcher Professor Hell has managed to break this barrier. Although smaller structures could be observed earlier with the electron or scanning probe microscope, the preparations had to be cut into wafer-thin slices so that examinations of intact or living cells were impossible. The novel method of light microscopy developed by Professor Hell offers a remedy here.
Observing gaps in DNA under the microscope As early as 1990, Professor Hell had developed the 4Pi microscope, which works not only with one but with two light sources, so that light from two sides falls on the observed object at the same time and thus the resolution by four - increases up to seven times. By using laser light for light microscopy, the resolution could be further improved and so the method of stimulated emission depletion microscopy developed by Prof. Hell offers the possibility to observe biological structures that are up to 2000 times finer than a hair (minimal 20 nanometers). In order to observe such tiny structures with so-called nanoscopy, the new method of light microscopy uses the properties of fluorescent dyes, which are also used in other medical procedures for marking cell structures. With the help of the special light microscopy he developed, Professor Hell was only recently able to visualize DNA strands, and in the future the expert, now awarded the Meyenburg Prize, hopes to detect repetitions or gaps in the DNA under the microscope. In this way, errors in the genome that can lead to various diseases and the development of tumors or cancer can be determined, the scientists hope.
The Meyenburg Prize, awarded to Professor Hell, has been awarded as a science prize since 1981 for important work in the field of cancer research and the fight against cancer and is funded by the Wilhelm and Maria Meyenburg Foundation. (fp)
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