Localization Microscopy Using GFP

Juli 30, 2009

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.

3D Movies of Microscopic Systems

Juli 29, 2009

Physicists at New York University (NYU), US have developed a technique to record three-dimensional movies of microscopic systems, such as biological molecules, through holographic video. The technique, developed in the laboratory of NYU Physics Professor David Grier, is comprised of two components: making and recording the images of microscopic systems and then analyzing these images. To generate and record images, the researchers created a holographic microscope. It is based on a conventional light microscope, which uses a collimated laser beam instead of on an incandescent illuminator.
When an object is placed into path of the microscope’s beam, the object scatters some of the beam’s light into a complex diffraction pattern. The scattered light overlaps with the original beam to create an interference pattern reminiscent of overlapping ripples in a pool of water. The microscope then magnifies the resulting pattern of light and dark and records it with a conventional digital video recorder. Each snapshot in the resulting video stream is a hologram of the original object. Unlike a conventional photograph, each holographic snapshot stores information about the three-dimensional structure and composition of the object that created the scattered light field. The recorded holograms appear as a pattern of concentric light and dark rings.
For analyzing the images the researchers based their work on a quantitative theory, the Lorenz-Mie theory, which maintains that the way light is scattered can reveal the size and composition of the object that is scattering it.
The application of the technique ranges from research in fundamental statistical physics to analyzing the composition of fat droplets in milk.

In the microscope, a laser beam illuminates the sample. Light scattered by the sample creates an interference pattern which is magnified and recorded. Then measurements of the particle’s position, size, and refractive index are obtained.

In the microscope, a laser beam illuminates the sample. Light scattered by the sample creates an interference pattern which is magnified and recorded. Then measurements of the particle’s position, size, and refractive index are obtained.

Spectroscopy Meeting

Juli 29, 2009

Thermo Fisher Scientific will hold its 2009 Spectroscopy User Meeting from September 14-15, 2009 in Stratford, UK. The event will cover an evening applications workshop on September, 14 and a free of charge scientific programme on September, 15. The scientific programme will feature talks from spectroscopy instrument users. In addition applications specialists will be providing an update on recent advances in the use of infra-red, near infra-red, Raman and UV spectroscopy. There will also be the opportunity to see current generation spectroscopy systems in operation and see how sample handling and data analysis tools have changed over the years.

Mobile Phone Microscopy

Juli 23, 2009

Researchers at the University of California, Berkeley, US have developed the CellScope – a new microscope that can be attached to a common mobile phone with a camera to take color images of microorganisms. The CellScope consists of compact microscope lenses fitted in a holder, which is positioned in front of the mobile phones camera. By using an off-the-shelf phone with a 3.2 megapixel camera, the researchers were able to achieve a spatial resolution of 1.2 micrometers. In this way they were able to capture bright field images of Plasmodium falciparum, the parasite that causes malaria in humans and sickle-shaped red blood cells. They were also able to take fluorescent images of Mycobacterium tuberculosis, the bacterium that causes TB in humans. The development of CellScope moves a major step forward in taking clinical microscopy out of specialized laboratories and into field settings for disease screening and diagnoses. „The same regions of the world that lack access to adequate health facilities are, paradoxically, well-served by mobile phone networks,“ said Dan Fletcher, UC Berkeley associate professor of bioengineering and head of the research team. „We can take advantage of these mobile networks to bring low-cost, easy-to-use lab equipment out to more remote settings.“

CellScope prototype configured for fluorescent imaging (taken by David Breslauer)

CellScope prototype configured for fluorescent imaging (taken by David Breslauer, UC Berkeley)

Fellow for the Microscopy Society of America

Juli 23, 2009

Harald Rose, professor of Physics at the Technical University of Darmstadt, Germany has been elected a Fellow for the Microscopy Society of America (MSA). Rose is a pioneer in electron microscopy: Together with his colleagues Maximillian Haider and Knut Urban he was the first to make single atoms visible by using electron microscopy. The designation of “MSA Fellow” is intended to recognize senior members of the society who have made significant contributions to the advancement of the science and practice of microscopy imaging, analysis and/or diffraction techniques. The fellowship certificate will be presented to him during the Microscopy and Microanalysis 2009 meeting in Richmond, VA, US.

Harald Rose, Professor of Physiscs at TU Darmstadt, Germany (source: www.idw-online.de)

Harald Rose, Professor of Physiscs at TU Darmstadt, Germany (source: http://www.idw-online.de)

MIT and INL Launch Research Collaboration

Juli 21, 2009

The International Iberian Nanotechnology Laboratory (INL), Braga, Portugal and the Massachusetts Institute of Technology (MIT), MA, US have announced a new collaboration that will enrich each institution’s research activities in nanoscience and nanotechnology. The two institutions will create MIT-INL, a new education and research enterprise focusing on nanotechnology. The collaboration will create 10 senior research positions for scientists who will launch a new nanotechnology research agenda, and it will enable approximately $35 million (€25 million) of new sponsored research with MIT in its first five years.

Canada Gains New Centre for Nanotechnology

Juli 20, 2009

Alberta, Canada will soon be home to a new research and product development centre for nanotechnology called Hitachi Electron Microscopy Products Development Centre (HEMiC) at the National Institute for Nanotechnology (NINT) in Edmonton. The centre will house three new electron microscopes valued at $7 million. The $14 million project is supported by the Western Economic Partnership Agreement between the Governments of Canada and Alberta and to contributions from Hitachi High-Technologies. The HEMiC is made possible by a wider collaboration of the Alberta Ingenuity Fund’s nanoWorks program, the National Institute for Nanotechnology of the National Research Council, the University of Alberta and Hitachi High Technologies Canada Inc. One of the centre’s first projects will evaluate and test the world’s sharpest electron emitter, developed by the Molecular Scale Devices group at NINT for use as an electron source in electron microscopes.