Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New NIST method evaluates response to oxidation in live cells

Researchers at the National Institute of Standards and Technology (NIST) have developed a new method for accurately measuring a key process governing a wide variety of cellular functions that may become the basis for a "health checkup" for living cells.

The NIST technique measures changes in a living cell's internal redox (reduction-oxidation) potential, a chemistry concept that expresses the favorability of reactions in which molecules or atoms either gain or lose electrons.

NMR data showing the levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) over time in yeast cells at rest (top) and under oxidative stress (bottom). The cells at rest have almost no GSSG (dark blue shades) but it spikes briefly when they are stressed, while GSH declines. This type of analysis may one day help to measure cell health.

Credit: Reipa/NIST

Redox reactions are important to cell chemistry because they regulate many genes and the proteins they produce. An accurate measure of redox potential can provide insight into how well these genes are working, and in turn, whether or not the activities they control—such as differentiation and growth—are functioning normally.

To assess this, scientists customarily measure the levels of both the reduced (electrons added) and oxidized (electrons lost) forms of glutathione, a peptide the cell uses as an antioxidant. Glutathione in cells is found predominately in the reduced state, known as GSH, but some gets converted to the oxidized form, known as GSSG. A high amount of GSSG indicates a cell has suffered oxidative stress, a process believed to contribute to cell aging, breakdown, malfunction (such as cancer) and eventual death.

Unfortunately, traditional methods of obtaining this data are akin to an autopsy. The only way to measure the relative amounts of GSH and GSSG within a cell has been to rupture its membrane—killing it—and then examine the released contents.

The NIST team developed a way to measure GSH and GSSG levels in living cells in real time using nuclear magnetic resonance (NMR)spectroscopy, a technique that images individual molecules similar to how doctors use magnetic resonance imaging (MRI) to noninvasively view organs. "NMR has been shown in recent years to be a powerful tool for studying metabolites as they operate in living cells, so we felt it could work well as a noninvasive way to do the same for GSH and GSSG," says NIST research chemist Vytas Reipa.

In their proof-of-concept experiment,* the NIST researchers grew a mutant strain of yeast cells that could not manufacture their own glutathione in a medium containing the peptide tagged with a nitrogen isotope. This ensured that the only glutathione available in the cells would be detectable using NMR during its conversion from GSH to GSSG.

GSH and GSSG levels were measured by NMR for both cells at rest and under oxidative stress, and then used to calculate the changing intracellular redox potentials over time. The results showed, for the first time ever, that redox potential can serve as an indicator of how cells perform in response to oxidation in real time.

"We know that when oxidation tips the balance toward too much GSSG, we get a redox potential shifted more to the positive than it should be," Reipa explains. "A healthy cell compensates by reversing the process and when that happens, the redox potential shifts back to its original value. A sick cell, on the other hand, does not compensate and the value stays positive. Therefore, an accurate in-cell measurement of redox potential could one day help us determine how well cells can recover from oxidative stress and, as a result, give us a picture of the cell's overall health."

Currently, the NIST researchers are exploring other NMR-detectable peptides involved in reduction and oxidation processes to conduct studies with mammalian cells.

The NMR spectroscopy in this experiment was conducted at NIST's Gaithersburg, Md., facility in collaboration with NIST scientists at the Hollings Marine Laboratory (HML) in Charleston, S.C., and the Institute for Bioscience and Biotechnology Research (IBBR) in Rockville, Md.

*S.Y. Rhieu, A.A. Urbas, D.W. Bearden, J.P. Marino, K.A. Lippa and V. Reipa. Probing the intracellular glutathione redox potential by in-cell NMR spectroscopy. Angewandte Chemie, 126: 457-460 (2014). DOI:

Michael E. Newman | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht International team discovers novel Alzheimer's disease risk gene among Icelanders
24.10.2016 | Baylor College of Medicine

nachricht New bacteria groups, and stunning diversity, discovered underground
24.10.2016 | DOE/Lawrence Berkeley National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>