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

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 2,600+ scientific posters on ePosters
  • More than 3,800+ 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 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

Promising Drug Candidate to Treat Chronic Itch
In a new study, scientists from the Florida campus of The Scripps Research Institute (TSRI) describe a class of compounds with the potential to stop chronic itch without the adverse side effects normally associated with medicating the condition.
Monday, October 05, 2015
How Small RNA Helps Form Memories
In a new study, a team of scientists at Scripps Florida has found that a type of genetic material called "microRNA" (miRNA) plays surprisingly different roles in the formation of memory in animal models.
Friday, August 21, 2015
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
Scripps' Scientists Develop Promising Drug Candidates for Pain and Addiction
Two new drug scaffolds offer researchers novel tools that act on the kappa opioid receptor.
Thursday, January 16, 2014
Scientific News
Enzyme Malfunction May be Why Binge Drinking Can Lead to Alcoholism
A new study in mice shows that restoring the synthesis of a key brain chemical tied to inhibiting addictive behavior may help prevent alcohol cravings following binge drinking.
Cell's Waste Disposal System Regulates Body Clock Proteins
New way to identify interacting proteins could identify potential drug targets.
Compound Doubles Up On Cancer Detection
Researchers have found that tagging a pair of markers found almost exclusively on a common brain cancer yields a cancer signal that is both more obvious and more specific to cancer.
Promising Drug Candidate to Treat Chronic Itch
In a new study, scientists from the Florida campus of The Scripps Research Institute (TSRI) describe a class of compounds with the potential to stop chronic itch without the adverse side effects normally associated with medicating the condition.
Are Changes to Current Colorectal Cancer Screening Guidelines Required?
Editorial suggests more research is needed to pinpoint age to end aggressive screening.
Assessing Cancer Patient Survival and Drug Sensitivity
RNA editing events another way to investigate biomarkers and therapy targets.
New Molecular Marker for Killer Cells
Cell marker enables prognosis about the course of infections.
Potential Target for Treatment of Autism
Grant of $2.4 million will support further research.
Sniffing Out Cancer
Scientists have been exploring new ways to “smell” signs of cancer by analyzing what’s in patients’ breath.
Inroads Against Leukaemia
Potential for halting disease in molecule isolated from sea sponges.

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
2,600+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos