A downscaled geophysical technique could be used to study biological processes such as wound healing, according to Swiss bioengineers.

The resistance of cells to an alternating current can yield information about cell and tissue structure and movement, said Pontus Linderholm. With colleagues from the Swiss Federal Institute of Technology in Lausanne, he created an electronic device that measures this resistance in a layer of cells grown on top of it. The system images vertical cross-sections of the cell layer, and provides more structural information than current electrical techniques.

According to the team, their method can gain information ranging from the density of cells in a tissue to the type of cells present. They successfully used the technique to study the migration of cells across a 'cut' made in a cell layer.

Linderholm said that the devices may be used to gain a better understanding of cell migration in the body, for instance in wound healing and the development of embryos.

He also sees potential for drug-screening: 'It is important to know what effect drugs have on cell mobility,' he said. He added that being able to screen hundreds of compounds simultaneously using electronics would save a lot of time compared to studying the effect of each compound on cell movement through a microscope.

The group borrowed their technique from geophysicians, who use resistance measurements on a much larger scale to study things like glaciers and groundwater flow. Although the idea of using this technique to image cells is about twenty years old, Brian Brown of the University of Sheffield, UK - himself a pioneer in the field - believes that this is the 'first significant development of a microsystem able to record cell migration'.

Danièle Gibney