New chip guides molecular analysis

A student at Johns Hopkins University, Maryland, has constructed a new type of microchip that can move and isolate DNA and protein molecules.

A Johns Hopkins University undergraduate has constructed a new type of microchip that can move and isolate DNA and protein molecules.

He believes that by linking the chip with analysis equipment, a user could identify medical ailments, monitor a patient’s health or detect viruses and other biohazards before they spread.

Eric Simone, a senior biomedical engineering student, fabricated and tested the chip in the lab of Jeff Tza-Huei Wang. Wang, an assistant professor in the Department of Mechanical Engineering, had already produced a biosensor chip with electrodes embedded in a straight line.

Under Wang’s supervision, Simone devised a biosensor chip with a circular electrode design, which performed more effectively in certain bio-analytical applications.

‘This chip gives us a new tool to look into biological questions,’ said Wang. ‘Eric can actually interact with and manipulate individual DNA molecules.’

‘The chip has tiny wires, each about one-fifth the diameter of a human hair, embedded in a circular pattern,’ Simone said. ‘When it’s connected to a power source, it allows us to generate an electric field that can transport molecules to a designated area for study.’

The chips made by Wang and Simone take are said to take advantage of the natural negative charge possessed by DNA or a surface charge imposed on the molecules. A tiny drop of liquid containing the DNA is placed on top of the chip. The electric field then guides the molecules to a designated area, where they can be analysed under a microscope.