Corporate Banner
Satellite Banner
Proteomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Chemists Devise Inexpensive, Benchtop Method for Marking and Selecting Cells

Published: Wednesday, January 16, 2013
Last Updated: Wednesday, January 16, 2013
Bookmark and Share
Chemists at The Scripps Research Institute have found an easier way to perform one of the most fundamental tasks in molecular biology.

Their new method allows scientists to add a marker to certain cells, so that these cells may be easily located and/or selected out from a larger cell population.

The technique, which is described in a recent issue of the chemistry journal Angewandte Chemie International Edition, makes use of the tight binding of two proteins that are cheaply obtainable but are not found in human or other mammalian cells. As such, it has advantages over existing cell-marking techniques.

“This new technique is cheap, easy and sensitive,” said TSRI Institute Professor Richard A. Lerner, who is the senior author of the new report. “The method should be useful in a variety of applications that require separating out certain types of cells.”

Looking for a Better Way

The best-known cell marker in use today is GFP (green fluorescent protein), a jellyfish protein that emits a distinctive green light when illuminated by certain other light wavelengths. When scientists want to add a new gene to cells, for example to produce a therapeutic protein, they often construct a genetic sequence that also includes the GFP gene. Thus the cells that successfully produce the new protein will also produce GFP, whose fluorescence allows these cells to be identified and even sorted out from a larger population.

But fluorescence-based cell sorting is relatively expensive and cumbersome. Alternative cell-marking techniques use marker molecules to which antibodies or metals will bind tightly, but these are apt to have unwanted side effects on the cells that they mark. Lerner’s team, led by first author Yingjie Peng, a postdoctoral fellow, set out to invent a better method.

The new method exploits a special property of chitinase enzymes, which evolved to break down chitin—a tough, sugar-derived material found, for example, in crab shells, squid beaks and the cell walls of fungi. In addition to a main chitin-breaking domain, chitinases have another active structure, a “chitin binding domain” (ChBD). “It makes a super-strong bond with chitin,” said Peng. In recent years, scientists have begun to use this high-affinity binding of ChBD and chitin as a marker system, typically for selecting ChBD-tagged proteins in a lab dish. The new method uses ChBD to mark and select cells.

A Powerful Tool

In the basic technique, a new gene can be added to cells within a larger DNA vector that also includes the genetic sequences for ChBD and GFP. The ChBD molecule will be produced in such a way that it ends up being held on the outer surface of its host cell’s plasma membrane—and the GFP molecule will sit just inside the membrane. The GFP serves as a visual beacon, while the ChBD serves as a handy gripping point for cell selection.

After exposing a culture of test cells to this experimental ChBD-containing vector, the scientists was able to see, via the GFP tags, which cells were expressing them, and was able to select them out easily, with high sensitivity, using magnetic beads coated with chitin. “This is a relatively easy benchtop method,” Peng said. Importantly, these selected cells could produce progeny cells that seemed normal and healthy.

Because the ChBD marker, in the vector, is produced in a way that anchors it to a cell’s membrane, it also can serve as a powerful tool for selecting just the membrane fraction of a sample of cellular material. Peng and his colleagues demonstrated this using chitin beads to quickly isolate a pure fraction of membrane material from ChBD-marked test cells.

Cellulase enzymes, which break down the ubiquitous plant compound cellulose, also have a high-affinity cellulase-binding domain, which can be employed in the same way as the ChBD.

The scientists expect that the new cell-marking method will help to streamline another major molecular biology technique, which was pioneered by the Lerner laboratory in parallel with the group of Sir Gregory Winter at the Laboratory of Molecular Biology in Britain. This technique allows scientists to produce very large and diverse libraries of antibody arms, and to sift through them, or “pan”—as gold miners pan for nuggets—for those that might be of use, for example in therapies. ChBD-based markers should be useful in boosting the efficiency of this panning process, said Peng.

The Lerner laboratory is also investigating the potential use of ChBD-based cell marking in living animals, for example to track the fates of selected cell types throughout an animal’s lifespan.


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Scripps Scientists Awarded NIH Grant for Biomarker Studies
$2.3 million grant awarded to develop new diagnostics for cancer, rheumatoid arthritis, colitis.
Tuesday, May 06, 2014
Scientists Solve 40-year Mystery of How Sodium Controls Opioid Brain Signaling
The findings pave way for new therapies for treating pain and mood disorders.
Thursday, January 16, 2014
Scientists Discover a New Type of Protein Modification that May Play a Role in Cancer and Diabetes
Scientists at The Scripps Research Institute (TSRI) have discovered a new type of chemical modification that affects numerous proteins within mammalian cells.
Tuesday, August 06, 2013
Scientists Discover How Two Proteins Help Keep Cells Healthy
The work has implications for cancer drug development.
Thursday, December 06, 2012
Team Reveals Key Protein Interactions Involved in Neurodegenerative Disease
New study reveals the structure of c-jun-N-terminal kinases (JNK) enzymes.
Thursday, November 15, 2012
Scientists Find Structure of a Protein that Makes Cancer Cells Resistant to Chemotherapy
A research team at the Scripps Research Institute has obtained the first glimpse of a protein that keeps certain substances, including many drugs, out of cells.
Monday, March 30, 2009
Scientific News
Lemon Juice and Human Norovirus
Citric acid may prevent the highly contagious norovirus from infecting humans, scientists discovered from the German Cancer Research Center.
Signature of Microbiomes Linked to Schizophrenia
Studying microbiomes in throat may help identify causes and treatments of brain disorder.
Structural Discoveries Could Aid in Better Drug Design
Scientists have uncovered the structural details of how some proteins interact to turn two different signals into a single integrated output.
Protein Found to Play a Key Role in Blocking Pathogen Survival
Calprotectin fends off microbial invaders by limiting access to iron, an important nutrient.
Study Identifies the Off Switch for Biofilm Formation
New discovery could help prevent the formation of infectious bacterial films on hospital equipment.
How DNA ‘Proofreader’ Proteins Pick and Edit Their Reading Material
Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have discovered how two important proofreader proteins know where to look for errors during DNA replication and how they work together to signal the body’s repair mechanism.
Protein Found to Control Inflammatory Response
A new Northwestern Medicine study shows that a protein called POP1 prevents severe inflammation and, potentially, diseases caused by excessive inflammatory responses.
X-ray Laser Experiment Could Help in Designing Drugs for Brain Disorders
Scientists found that when two protein structures in the brain join up, they act as an amplifier for a slight increase in calcium concentration, triggering a gunshot-like release of neurotransmitters from one neuron to another.
Team Identifies Structure of Tumor-Suppressing Protein
An international group of researchers led by Carnegie Mellon University physicists Mathias Lösche and Frank Heinrich have established the structure of an important tumor suppressing protein, PTEN.
Why We’re Smarter Than Chickens
Toronto researchers have discovered that a single molecular event in our cells could hold the key to how we evolved to become the smartest animal on the planet.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!