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 Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Solar Collectors from Ultra-High Performance Concrete Combine Energy Efficiency and Aesthetics

16.01.2017 | Trade Fair News

3D scans for the automotive industry

16.01.2017 | Automotive Engineering

Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs

16.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>