Researchers at Fujitsu Laboratories and The Technical University of Munich are working on technology that may one day lead to the development of a fast, accurate and portable detector for chronic diseases and viruses.

The project is developing a portable protein detector that will use a new approach to analyzing DNA (deoxyribonucleic acid). Detection of proteins is a valuable tool in healthcare because the presence of one or a combination of proteins in a sample can serve as an indicator for a particular disease such as diabetes or a virus such as SARS (severe acute respiratory syndrome).

"Protein detection will become much more important in future health care," said Shozo Fujita, senior research fellow at Fujitsu's Nanotechnology Research Center in Atsugi, west of Tokyo.

Machines already exist to carry out such detection but they're large and typically only used in hospitals, he said.

"We'd like to develop a machine that is very portable," he said.

Fujitsu Labs' vision is of a small and compact terminal that can be used bed-side in hospitals, in people's homes, in ambulances or in places like airports and railway stations. To realize this, a new approach is being employed that relies on changes in the movement of minute strands of DNA to determine whether a particular protein is present in a sample.

DNA strands, each about 10 nanometers long, are anchored at one of their ends to a gold electrode. On the free end is some florescent dye and an antibody that binds to the protein being detected.

The strands carry a charge and by applying an alternating positive and negative charge to the electrode can be made to stand up or lie down. When a laser is shined on the strands this up-and-down movement can be recorded as a change in the fluorescence, which is brighter when the DNA is standing and lower when it is lying down.

When a sample is introduced that contains the protein being detected, the proteins bind to the antibodies on the ends of the DNA strands and that slows down their movement. This leads to a change in the fluorescence detected and that change indicates that binding has occurred and thus the protein is present.

"It takes about one hour to get a result but we'd like to get this down to 1 minute or several minutes," Fujita said.

The IDG News Service is a Network World affiliate.