Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel "Canary on a Chip" Sensor Measures Tiny Changes in Cell Volume; Provides Assay Results in Minutes

14.02.2005


A novel technology that can test cells in minutes for responses to any stimulus, including antibiotics, pathogens, toxins, radiation or chemotherapy, has been developed by scientists at the University at Buffalo.

The paper describing the sensor will appear in the Feb. 15 issue of Analytical Chemistry, and currently is available as an "ASAP" article on the American Chemical Society Web site http://www.chemistry.org.

Susan Z. Hua, Ph.D., UB assistant professor of mechanical and aerospace engineering and physiology and biophysics, is the lead researcher. The technology is based on the universal connection between cell volume and the cell environment, or cell volume cytometry. It is particularly useful because it eliminates the need to culture bacteria to assess their sensitivity to antibiotics. "Now, in a matter of minutes, we can tell if particular antibiotics are active against specific bacteria," said Frederick Sachs, Ph.D., professor of physiology and biophysics at UB, co-director of UB’s Center for Single Molecule Biophysics and a coauthor on the paper. "We have measured the sensitivity to antibiotics of different strains of E. Coli in less than 10 minutes at room temperature. We will get results even faster at higher temperatures."



Hua and her students created the tiny silicon chip that is the heart of the sensor chamber in which the cells are encased for testing. "The new technique is so sensitive it can detect changes in cell dimensions never seen before in living cells," she said. "The necessary power can be supplied even by a watch battery and the sensor is so small it could fit into a pencil eraser." Sachs said the assay can be used on any biological component that is enclosed by a membrane. "It doesn’t have to be cells. We can use lipid bilayer vesicles containing a single protein, mitochondria, chloroplasts (plant cells) or cell nuclei, as well as whole cells. We can screen for just about anything."

For example, this technique could be used to rapidly scan cancer cells obtained from biopsies to evaluate the effectiveness of chemotherapy or radiation protocols. The chip has obvious application to measuring toxins relevant to bioterrorism, Sachs said.

Cell volume and physiological function are intimately intertwined, the authors note in their paper. Normal biological activity, such as metabolism, apoptosis (programmed cell death) or cell division affect cell volume, as does abnormal activity, such as exposure to toxic agents. Sachs and Hua call the sensor a "canary on a chip," to highlight its versatility as a first-line indicator of activity.

There are many methods used to measure changes in cell volume, said Hua, but electrical impedance, the resistance to flow of electric current, is the key to this sensor’s simplicity. Cells are electrical insulators, she noted. "When immersed in salt water, which conducts current, the cells displace some of the water and reduce the electrical current. If cells swell, as commonly would happen in the presence of a toxin, the resistance would increase and the current would become smaller, indicating a cellular response."

In addition to being simple to use, the chip is inexpensive, low power, portable and provides real-time results, said Sachs. "The assay is applicable to an enormous number of problems, and is a particularly powerful tool for drug screening," he noted.

Additional authors on the study are Daniel A. Ateya, a UB mechanical engineering student; Philip A. Gottlieb, Ph.D., research associate professor in the UB Center for Molecular Biology and Immunology, and Steve Besch, Ph.D., research assistant professor of physiology and biophysics. The authors have filed a patent on the technology.

The work was supported by grants to Hua and Sachs from the National Science Foundation and the National Institutes of Health, respectively. The microfabrication was done primarily in the Nanofabrication Facility at Cornell University.

Lois Baker | EurekAlert!
Further information:
http://www.buffalo.edu
http://www.chemistry.org

More articles from Health and Medicine:

nachricht New vaccine production could improve flu shot accuracy
25.07.2017 | Duke University

nachricht Chances to treat childhood dementia
24.07.2017 | Julius-Maximilians-Universität Würzburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>