Molecular Movement Steps Up DNA Research

The chance to unravel the mysteries shrouding DNA was the seed that sprouted a novel microchip design. Eric Simone, a senior biomedical engineering major at Johns Hopkins University, fabricated and tested a chip that moves and isolates DNA and protein molecules. The chip takes advantage of the natural negative charge possessed by DNA or a surface charge on the molecules. Researchers can place a drop of liquid containing DNA on the chip, which is connected to a power source. An electric field then guides the molecules to a designated area, where they can be analyzed under a microscope.

By linking this chip with analysis equipment, doctors eventually will be able to identify medical ailments, monitor patient health, and detect viruses and other biohazards before they spread. Simone worked under the direction of assistant professor Jeff Tza-Huei Wang of the Department of Mechanical Engineering. Previously, Wang produced a biosensor chip with electrodes embedded in a straight line. Simone's chip instead uses a circular electrode design that performs more effectively in certain bio-analytical applications. Each wire on the chip is only one-fifth the diameter of a human hair.

For details, go to www.jhu.edu.

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