A protein's life, up close and personal

January 7, 2013 by Nicolas Guérin

(Phys.org)—An EPFL team has developed a technique for spying on the inner lives of cells. For the first time, scientists have used a near-infrared, light-sensitive biocompatible molecule to mark and observe the activity of proteins inside living cells.

Proteins are the building blocks of all life, responsible for innumerable functions in cells, including communication, structural maintenance and mobility. But they're quite difficult to study. One method is to observe their distribution and work they do inside living cells. Now EPFL scientists have, for the first time, used a molecule that can penetrate the cell membrane, attach to proteins and then shine when exposed to near-infrared light. This development will make it possible to probe living tissues without damaging them and will reveal, in real time, the that are taking place.

This video is not supported by your browser at this time.

Just light enough

Thanks to genetics and chemistry, EPFL scientists were able to attach membrane-penetrating, near-infrared-sensitive to proteins inside a cell, without causing any damage to the cell in the process. The challenge of studying proteins in vivo is that living tissue is both fragile and opaque to certain . Up to now, researchers had to force light in order to see fine detail or pass through the thickness of the tissue. But the used are harmful at high doses.

With funding from the NCCR , a team led by Suliana Manley from EPFL's Laboratory of Experimental Biophysics and Kai Johnsson from EPFL's Laboratory of has realized a long-held dream in biology. They have developed a fluorescent substance - a "fluorophore" - that can penetrate the , react to near- and make proteins shine unusually brightly, thus making it easy to observe them using a microscope.

A promising technique

"The advantages of the molecule that we've developed are that it's stable, easy to couple to proteins and shines strongly enough," explains Gražvydas Lukinavičius. "People have been trying for about a decade to develop a molecule like this that can enter into living cells in order to observe tissues in depth," adds his colleague Kai Johnsson.

Thanks to this molecule, the chemists have obtained promising results. In particular, they were able to apply the "super-resolution" method, in which a mathematical treatment is used to improve image resolution. With this method, the tiniest details visible in living tissues are thus about 50-60 nanometers, four times better than using a conventional microscope. This technique also allows images to be taken very rapidly, in order to recreate three-dimensional images or animations that reveal the processes taking place.

Explore further: New protein tag enhances view within living cells

More information: lip.epfl.ch/
leb.epfl.ch/

Related Stories

New protein tag enhances view within living cells

February 22, 2008

The view into the inner world of living cells just got a little brighter and more colorful. A powerful new research tool, when used with other labeling technologies, allows simultaneous visualization of two or more different ...

A closer look at cells

July 27, 2011

Many substances and nutrients are exchanged across the cell membrane. EPFL scientists have developed a method to observe these exchanges, by taking a highly accurate count of the number of proteins found there. Their research ...

Proteins shine a brighter light on cellular processes

March 20, 2012

Scientists have designed a molecule which, in living cells, emits turquoise light three times brighter than possible until recently. This improves the sensitivity of cellular imaging, a technique where biological processes ...

Recommended for you

Findings illuminate animal evolution in protein function

July 27, 2015

Virginia Commonwealth University and University of Richmond researchers recently teamed up to explore the inner workings of cells and shed light on the 400–600 million years of evolution between humans and early animals ...

New polymer able to store energy at higher temperatures

July 30, 2015

(Phys.org)—A team of researchers at the Pennsylvania State University has created a new polymer that is able to store energy at higher temperatures than conventional polymers without breaking down. In their paper published ...

How to look for a few good catalysts

July 30, 2015

Two key physical phenomena take place at the surfaces of materials: catalysis and wetting. A catalyst enhances the rate of chemical reactions; wetting refers to how liquids spread across a surface.

Yarn from slaughterhouse waste

July 29, 2015

ETH researchers have developed a yarn from ordinary gelatine that has good qualities similar to those of merino wool fibers. Now they are working on making the yarn even more water resistant.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.