Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Tagging Technique Enhances View of Living Cells

05.08.2010
Scientists hoping to understand how cells work may get a boost from a new technique to tag and image proteins within living mammalian cells.

The new technique, developed by a research team led by University of Illinois at Chicago assistant professor of chemistry Lawrence Miller, provides the clearest, most dynamic view yet of protein-protein interactions in cells when viewed through a specially modified microscope.

The finding is reported in the Proceedings of the National Academy of Sciences (advanced online July 19.)

Knowing where and when particular proteins interact within the cell is key to understanding life processes at the molecular level.

In a technique called luminescence resonance energy transfer, two proteins in a cell are labeled with differently colored, luminescent molecules that absorb light of one color and give it off as another color. By taking several pictures of the cell and mathematically analyzing the pictures, researchers gain information about the proteins' precise location and whether they are interacting.

Miller and his team used a novel type of luminescent molecule for labeling, making it possible to get the same information using fewer pictures. This simplifies the analysis and allows for five-fold faster data acquisition. Images show a 50-fold improvement in sensitivity.

Working with Jerrold Turner, professor and associate head of pathology at the University of Chicago, Miller used a hybrid chemical/genetic approach to tag the proteins of interest. One of the proteins was genetically modified so that it would bind to a terbium complex. The terbium complex has an unusually long time between light absorption and emission. The second target protein was genetically modified to link to a fluorescent tag with a short emission lifetime. When the two proteins interact, the luminescent tags are brought very close together, generating a unique luminescent signal that can be seen under a microscope.

Miller and his colleagues modified a conventional microscope to exploit the long lifetime of the terbium protein tags. Pulsed light is used to trigger the terbium luminescence, detected after the other luminescent species within cells have gone dark, allowing unwanted background to be removed from the image.

The new technique "increases sensitivity and makes the whole process faster," Miller said. "This increases the time-resolution of the experiment, allowing you to see how interactions change on a faster time scale, which can help to better figure out how certain biological phenomena work."

The technique required a reliable way to deliver the luminescent terbium probe through a living cell membrane without contaminating or damaging the cell. The researchers developed a way to co-opt pinocytosis, the process by which cells drink in small amounts of surrounding fluid.

"With this new tool, we hope cell biologists and others will be able to study things they haven't seen before, such as interactions that couldn't be visualized in live cells in real time," Miller said. "Hopefully the method will yield information that makes it easier to deduce biological mechanisms."

Other authors include UIC graduate students Harsha Rajapakse (the lead author), Nivriti Gahlaut and Shabnam Mohandessi and University of Chicago graduate student Dan Yu. The terbium tag was developed in collaboration with Richmond, Calif.-based Lumiphore, Inc. Major funding was provided by the National Institutes of Health and the Chicago Biomedical Consortium.

Paul Francuch | Newswise Science News
Further information:
http://www.uic.edu

More articles from Life Sciences:

nachricht The dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg

nachricht Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

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 >>>