April 19, 2010 - Fujitsu Labs and Germany's Technische Universität München (TUM) say they have developed a new biosensor technology that uses DNA movement to detect proteins.

The technology works by inducing a cyclical motion in negatively charged DNA and measuring its movement, enabling quick detection of proteins -- accurately measuring proteins in 1/100th the time of previous methods, the groups claim.

Scientific and biological research continues to progress with identification of proteins causing ailments such as diabetes and cancer. Being able to more quickly detect the type, amount, and size of proteins enables earlier discovery of diseases, and more accurate and timely treatments.

Conventional methods to detect such proteins involve a multistep process requiring not insignificant quantities of samples (e.g., blood) for testing, and time and costs are high.

The new technology takes advantage of a DNA's negative charge when in an aqueous solution. An electrode is cycled between positive and negative charges, which alternately attracts and repels the DNA. A fluorescent dye applied to the ends of the DNA allows them to act as reference points, shining when the DNA is repelled from the electrode and dimly lit when attracted to it -- thus the movement of the DNA is made visible. (In addition to the graphic below, a video describes the process.)

Enabling visibility of DNA movement. (Source: Fujitsu Labs.)

Molecules predisposed to bond strongly with the target protein are attached to the ends of the DNA where the dyes were applied. Once the two are bonded, the DNA's movement is impeded by the molecules, enabling researchers to see the presence (or absence) of the target protein as well as how much has bonded. Rapidly cycling the electrode's positive and negative charges can derive the bonded protein's movement, and shape/size of the protein.

The biosensor technology can accurately measure proteins in 1/100th the time required with existing methods, and requiring only 1/100th the sample volume. And because it can not only detect the presence of proteins but also measure their size, it achieves superior precision, and applicability in a wider range of fields, the researchers say.

The TUM researchers, supported by Fujitsu Labs, aim to commercialize the technology through the German government's "EXIST" incubator program; business plans based on the technology won recent German business plan competitions.