COLLEGE STATION, Sept. 9, 2010 DNA analysis is poised to experience a significant advancement thanks to the work of a Texas A&M University chemical engineer, who has discovered a way to achieve more effective separation of DNA fragments.
Working with a widely used gelatin substance known as a hydrogel, Victor M. Ugaz, associate professor in the university's Artie McFerrin Department of Chemical Engineering, and graduate student Nan Shi have been able to determine the specific type of conditions that result in the optimum gel pore structure for separation of a wide range of DNA fragment sizes. Their findings appear in the Sept. 3 edition of the journal Physical Review Letters.
"It changes the way you think about the entire process because these findings demonstrate a rational way to connect the pore structure of the gel quantitatively to the mechanism by which the DNA moves through the gel," Ugaz explains. "Researchers can now actually design gels to specifically harness certain effects, and they will need this information we have found to do that."
The enhanced separation technique, Ugaz notes, could benefit a wide array of fields that utilize DNA analysis, including biomedical research, forensics and genetic engineering.
Key to Ugaz's findings is the manner in which DNA fragments move through a hydrogel. Employing a process called "electrophoresis," researchers who study DNA typically embed negatively charged DNA into a porous hydrogel. They then apply an electric field which causes the DNA fragments to move through the pores of the hydrogel. Naturally, smaller DNA chains move faster through the maze of pores than longer strands of DNA.
However, when DNA chains are roughly the same size as the pores through which they are attempting to pass, a process called "entropic trapping" takes place, Ugaz notes. During this process, the naturally coiled DNA fragment, in a sense, has to unthread a bit to pass through a pore
|Contact: Ryan Garcia|
Texas A&M University