To Study Biological Molecules and Structures

August 31, 2009

Researchers in the United States and Spain have discovered that a tool widely used in nanoscale imaging works differently in watery environments, a step toward better using the instrument to study biological molecules and structures.

The researchers demonstrated their new understanding of how the instrument – the atomic force microscope – works in water to show detailed properties of a bacterial membrane and a virus called Phi29, said Arvind Raman, a Purdue professor of mechanical engineering. An atomic force microscope uses a tiny vibrating probe to yield information about materials and surfaces on the scale of nanometers, or billionths of a meter. Because the instrument enables scientists to „see“ objects far smaller than possible using light microscopes, it could be ideal for studying molecules, cell membranes and other biological structures. The best way to study such structures is in their wet, natural environments. However, the researchers have now discovered that in some respects the vibrating probe’s tip behaves the opposite in water as it does in air, said Purdue mechanical engineering doctoral student John Melcher. The probe is caused to oscillate by a vibrating source at its base. However, the tip of the probe oscillates slightly out of synch with the oscillations at the base. This difference in oscillation is referred to as a „phase contrast,“ and the tip is said to be out of phase with the base.

Although these differences in phase contrast reveal information about the composition of the material being studied, data can’t be properly interpreted unless researchers understand precisely how the phase changes in water as well as in air, Raman said.

If the instrument is operating in air, the tip’s phase lags slightly when interacting with a viscous material and advances slightly when scanning over a hard surface. Now researchers have learned the tip operates in the opposite manner when used in water: it lags while passing over a hard object and advances when scanning the gelatinous surface of a biological membrane.

Researchers deposited the membrane and viruses on a sheet of mica. Tests showed the differing properties of the inner and outer sides of the membrane and details about the latticelike protein structure of the membrane. Findings also showed the different properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria.

Original Publication:

Melcher J, Carrasco C, Xu X, Carrascosa JL, Gómez-Herrero J, José de Pablo P, Raman A. (2009): Origins of phase contrast in the atomic force microscope in liquids. Proc Natl Acad Sci U S A. 2009 Aug 18;106(33):13655-60. Epub 2009 Aug 5.

Researchers in the United States and Spain have discovered that an atomic force microscope - a tool widely used in nanoscale imaging - works differently in watery environments, a step toward better using the instrument to study biological molecules and structures. The researchers demonstrated their new understanding of how the instrument works in water to show details of the mechanical properties of a virus called Phi29. The images in "a" and "c" show the topography, and the image in "b" shows the different stiffness properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria. (C. Carrasco-Pulido, P. J. de Pablo, J. Gomez-Herrero, Universidad Autonoma de Madrid, Spain)

Researchers in the United States and Spain have discovered that an atomic force microscope - a tool widely used in nanoscale imaging - works differently in watery environments, a step toward better using the instrument to study biological molecules and structures. The researchers demonstrated their new understanding of how the instrument works in water to show details of the mechanical properties of a virus called Phi29. The images in "a" and "c" show the topography, and the image in "b" shows the different stiffness properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria. (C. Carrasco-Pulido, P. J. de Pablo, J. Gomez-Herrero, Universidad Autonoma de Madrid, Spain)

http://news.uns.purdue.edu


Euro-BioImaging: First Stakeholder Meeting

Juli 17, 2009

From September 21-22, 2009 the first stakeholder meeting of Euro-BioImaging will take place at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany. The goal of Euro-BioImaging project is to establish a pan-European imaging infrastructure for biological and medical research. It will provide access to state of the art imaging technologies, training and a continuous development of imaging research technologies. The aim of the stakeholder meeting is to gather eminent representatives of the scientific community, funding and governmental organisations, and industry with particular interest in biomedical imaging and to discuss potential participation as well as the content and structure of this infrastructure project. Register online at:
www.embl.de/conferences/eurobioimaging


First Taiwan AFM Bioworkshop

Juni 30, 2009

Asylum Research, in conjunction with the National Health Research Institutes (NHRI), will host the first Taiwan AFM Bioworkshop to be held July 30-31, 2009 at NHRI, Zhunan Campus, in Taiwan. The workshop will combine talks from leading researchers and industry experts on atomic force microscopy for life science applications, as well as instructional AFM demonstrations. Topics covered include principles of AFM, biological imaging, force spectroscopy, integration of AFM and optical microscopy, sample preparation, application examples and future directions in AFM. The event is free to all researchers in the field of AFM.
www.asylumresearch.com/bioworkshop


$2 Million Grant for Live Microscopy

Mai 13, 2009

A proposal by a team of UC Davis (University of California, US) scientists to develop the first electron microscope capable of filming live biological processes has been awarded a $2 million grant from the National Institutes of Health. The team’s plan is to extend the capabilities of a powerful new imaging tool called the dynamic transmission electron microscope or DTEM. These instruments can snap 10 to 100 images per millionth of a second, while capturing details as small as 10 nanometers. If they can be adapted to living, moving systems, DTEMs could achieve resolutions 100 times greater than currently attainable for live processes, enabling scientists to observe and record biological processes at the molecular level. Currently, there are only three DTEMs in use worldwide, none of which are designed for observing living systems. Rather, they are utilized to document such processes as inorganic chemical reactions and the dynamics of materials as they change from one state – solid, liquid or gas – to another.
www.ucdavis.edu


3D in 12 Days

April 30, 2009

During June, 13-25, the 14th annual Living Cell Course will take place at the University of British Columbia Medicine School (UBC) in Vancouver, Canada. This residential course concentrates on all aspects of the 3D microscopy of living cells. Designed for biological research scientists and advanced graduate students, who apply – or plan to – modern 3D imaging, the course want to open up-to-date methods to a wider selection of scientists. The aim of this intense course is to bring students and manufacturers together. The course’s topics include amongst others scanning systems like AODs, mirrors and disks, deconvolution of wide-field and confocal data, dye design, poisson noise QE and S/N, calcium imaging, as well as „how to keep cells alive“.
www.3dcourse.ubc.ca/index.htm

Vancouver, Canada (sorce: pixelio.de)

Vancouver, Canada (sorce: pixelio.de)