Until now, the efficacy of test substances has been tested by using the nutrient medium to wash single cells into the cavities of microfluidic chips. The cavities are intended to contain single cells, but this method of washing in often leads to several cells or cells of different sizes being washed in, resulting in varying test results. This makes it necessary to test many cells in order to obtain a statistical average, which is time-consuming.

The new method is now able to address this problem. The newly constructed optical tweezers uses the force of a laser beam to manoeuvre single cells in the desired size into the cavity. This can reduce the save the work involved by as much as 80 percent, according to a press release by the Fraunhofer IPT.

Source and further information (German):
http://www.fraunhofer.de/de/presse/presseinformationen/2014/Januar/neue-pharmazeutika-besser-testen.html