Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Voltage tester for beating cardiac cells


Electrical impulses play an important role in cells of the human body. For example, neurons use these impulses to transmit information along their branches and the body also uses them to control the contraction of muscles.

The impulses are generated when special channel proteins open in the outer envelope of the cells, allowing charged molecules (ions) to enter or exit the cell. These proteins are referred to as ion channels.

Since the 1970s, a method has been available to researchers that enables measurement of the activity of these channels, but until now this method has been used primarily on cells that do not move. Electrical engineers at ETH Zurich and biologists from the University of Bern have now developed the method further, so that they can easily record the activity of moving cells, such as beating cardiac muscle cells in a tissue culture dish.

The existing method involves positioning a glass pipette against the outer membrane of a cell. The opening at the tip of the pipette is so small that it touches only a fraction of the cell surface. Ideally, this tiny patch of cell membrane has exactly one ion channel.

The inside of the pipette is filled with a conductive fluid and an electrode, which makes it possible to measure differences in the charge between the outer part of the cell and cell interior (i.e. an electric potential ) and temporary changes in this potential resulting from activity in the ion channels. The method is referred to as the patch-clamp technique because the pipette is used to clamp a patch of the cell membrane.

Atomic force microscope with micro-injection needle

Lead by Tomaso Zambelli, a lecturer at the Institute of Biomedical Engineering at ETH Zurich, and Hugues Abriel, a professor at the Department of Clinical Research at the University of Bern, the researchers have now combined this technique with an atomic force microscope. A sensor tip is seated on a movable mount - a so called cantilever - to scan the surface of the microscopic object.

Several years ago, the researchers succeeded in producing sensor tips with an internal channel, which allows the computer-controlled injection of molecules into a cell. This technique is now being marketed by the ETH spin-off Cytosurge. However, the scientists continued development of this technique by fitting the micro-injection needle with an electrode to carry out patch-clamp measurements. The researchers have now published the successful results of this venture in the journal Nano Letters.

The patch-clamp technique is not only a central method for basic research in cell biology, it is also used routinely in the development of new drugs. For example, the pharmaceutical industry is legally required as part of the approval process for new drugs to test whether these drugs interact with ion channels. A drug that blocks ion channels may cause severe cardiac dysrhythmia in patients, which should be avoided at all costs.

Longer measurements and automation possible

In the case of the conventional patch-clamp technique, an operator manually positions the pipette against the cell; although automated procedures exists, their applications are limited. Thus, the cells under test must have the same size and shape and must not move (as cardiac cells do).

In the case of the new method, the micro-needle is controlled by a computer using force measurements from the atomic force microscope to hold it at a constant short distance from the cell surface. "This makes the contact between the needle and cell much more stable, which allows us to take measurements over a longer period of time and even test moving cells," explains Zambelli. For the first time, researchers have thus succeeded in measuring electric potential changes in the ion channels of beating cardiac cells. Zambelli says he can also imagine using this as a foundation for development of an automated method for testing any cell, regardless of its shape or size.


Literature reference

Ossola D, Amarouch MY, Behr P, Vörös J, Abriel H, Zambelli T: Force-Controlled Patch Clamp of Beating Cardiac Cells. Nano Letters 2015, doi: 10.1021/nl504438z

Media Contact

Tomaso Zambelli


Tomaso Zambelli | EurekAlert!

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

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

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>