Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers demonstrate new technique that improves the power of atomic force micrscopy

17.08.2004


An artist’s depiction shows an atomic force microscope probe (not to scale) ’fishing’ for molecular sites recognized by an antibody tethered to the probe by a fine polymer thread. The new technique promises to vastly improve the capabilities of atomic force microscopy.


A team of researchers have developed a method that could vastly improve the ability of atomic force microscopes to "see" the chemical composition of a sample, follow variations of the sample, as well as map its topographic structure.

The advance could have significant implications for drug development by allowing scientists to monitor the effects of potential drugs on an ever-smaller scale, according to Stuart Lindsay, director of the Center for Single Molecule Biophysics at the Biodesign Institute at Arizona State University and a lead researcher on the project.

Lindsay, an ASU professor in the department of physics and astronomy said the new technique allows an atomic force microscope to "see," on a nanometer scale, the chemical composition of molecules.



"Atomic force microscopy has a resolution down to an atomic level, but until now it has been blind to identifying specific chemical compositions," Lindsay said.

The researchers -- Lindsay, Hongda Wang, Ralph Bash, Brian Ashcroft, and Dennis Lohr of Arizona State University; Cordula Stroh, Hermann Gruber and Peter Hinterdorfer of the Institute of Biophysics at the University of Lintz, Austria; and Jeremy Nelson of Molecular Imaging Corporation, Tempe, Ariz. -- present their findings in "Single Molecule Recognition Imaging Microscopy" in the current issue of the Proceedings of the National Academy of Sciences. The article is available on line at http://www4.nationalacademies.org/nas/nashome.nsf

"If you imagine that all proteins are shaped like Lego blocks, then conventional atomic force microscopy (AFM) is feeling the Lego blocks on the floor, but it can’t tell the difference between one block and another," Lindsay explained. "What we have done, is allow the person sitting on the floor and feeling those blocks to open their eyes and see that there are red Lego blocks, green Lego blocks and yellow Lego blocks."

"This allows you to identify specific components in an image," he added. "It means you can now follow a complex process and see what’s happening, at the molecular level, to one of the components. We are now giving AFM chemical sensitivity in much the way colored dyes gave optical microscopes optical sensitivity for much larger objects (~1 micron)."

Atomic force microscopes provide images on the nanometer scale by using a highly sensitive and tiny probe that is essentially pulled across a surface. By doing this, researchers can obtain topographical images down to a nanometer scale.

To use the AFM in its new mode, the researchers attached antibodies keyed to individual proteins to the tip of an AFM’s probe. When an antibody reacts with the protein it is specifically targeted for, it creates a variance in the microscope’s reading compared to a reading with a bare tip, thus showing the presence of a protein or other specific material in the region being scanned.

To help ensure that the antibody tipped probe is truly sensitive, a strand of polymer connects the antibody to the tip, providing a tether that allows the antibody to wiggle into position to better connect with the protein receptors. A magnetically excited cantilever makes the tip oscillate up and down to make the antibody disconnect and reconnect and keep the probe moving.

A key capability of this technique, Lindsay said, is that it allows researchers to see how components of a cell react on a molecular scale when they experience biological processes, such as their response to a specific chemical or compound. In this mode, it could provide researchers with a molecular "time-lapsed movie" of such reactions, which could lead to greater understanding of the chemical dynamics involved in how cells react to such stimuli.

Lindsay said the new AFM method could be significant for drug discovery.

"This development opens up the AFM as a research tool," Lindsay added. "The ability to identify the specific proteins on a membrane surface means you can take something very complex, like the surface of a human cell with all of the types of different receptors on it and ask questions about the local chemistry, like what is binding at those sites. That will provide the fundamental knowledge you need to develop new drugs."

Skip Derra | EurekAlert!
Further information:
http://www.asu.edu

More articles from Life Sciences:

nachricht New Computer Model Could Explain how Simple Molecules Took First Step Toward Life
29.07.2015 | Brookhaven National Laboratory

nachricht Switch for building barrier in roots
29.07.2015 | The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>