Professor Albena Ivanisevic and physics graduate student Dorjderem Nyamjav have developed a technique to make it easier to read life's genetic "blueprint." They have precisely placed strands of DNA on a silicon chip and then stretched out the strands so that their encoded information might be read more clearly, two steps critical to possibly using DNA for future electronic devices and computers.

PHOTO CAPTION: Physics doctoral student Dorjderem Nyamjav, left, and Albena Ivanisevic, an assistant professor of biomedical engineering at Purdue University, review an image taken with an atomic force microscope. The researchers have developed a method for precisely placing strands of DNA on a silicon chip and then stretching out the strands so that their encoded information might be clearly read, two steps critical to possibly using DNA for future electronic devices and computers. (Purdue News Service photo/David Umberger)

Ivanisevic and Nyamjav created templates containing charged lines of commercially available polymer. The positively charged polymer has the opposite charge as DNA, so when the genetic material is dropped onto the chip, it is attracted to the lines automatically. Then the researchers used a syringe to drag the DNA, uncoiling the strands along the template surface.

"The charged structures enable us to direct biological molecules in a certain location," Ivanisevic said.

Although other researchers have deposited DNA onto similar templates, Ivanisevic is the first to demonstrate how to also stretch strands of DNA in specific locations on such templates, which contain features so small they are measured in nanometers. This step could lead to the ability to stretch DNA molecules in specific locations on electronic chips, which is critical in harnessing the storage capacity of DNA for future computers.

DIAGRAM CAPTION: This diagram depicts the process of depositing DNA onto a chip containing lines of a polymer that has the opposite charge as DNA, causing the genetic material to be attracted automatically to the polymer. The researchers then stretched the DNA along the lines of polymer, uncoiling the genetic material so that its coded information might be read clearly. Inset images taken with an atomic force microscope show the lines and the DNA molecules. The work was done by Albena Ivanisevic, an Purdue University assistant professor of biomedical engineering, and physics doctoral student Dorjderem Nyamjav. Results are being published in the journal Advanced Materials. (Purdue University Department of Biomedical Engineering/Albena Ivanisevic)

Source: http://news.uns.purdue.edu/UNS/html4ever/031007.Ivanisevic.DNA.html