MADISON - Pity the molecular biologist.

The object of fascination for most is the DNA molecule. But in solution, DNA, the genetic material that hold the detailed instructions for virtually all life, is a twisted knot, looking more like a battered ball of yarn than the famous double helix. To study it, scientists generally are forced to work with collections of molecules floating in solution, and there is no easy way to precisely single out individual molecules for study.

Now, however, scientists have developed a quick, inexpensive and efficient method to extract single DNA molecules and position them in nanoscale troughs or "slits," where they can be easily analyzed and sequenced.

The technique, which according to its developers is simple and scalable, could lead to faster and vastly more efficient sequencing technology in the lab, and may one day help underpin the ability of clinicians to obtain customized DNA profiles of patients.

The new work is reported this week (Feb. 8, 2007) in the Proceedings of the National Academies of Science (PNAS) by a team of scientists and engineers from the University of Wisconsin-Madison.

"DNA is messy," says David C. Schwartz, a UW-Madison genomics researcher and chemist and the senior author of the PNAS paper. "And in order to read the molecule, you have to present the molecule."

To attack the problem, Schwartz and his colleagues turned to nanotechnology, the branch of engineering that deals with the design and manufacture of electrical and mechanical devices at the scale of atoms and molecules. Using techniques typically reserved for the manufacture of computer chips, the Wisconsin team fabricated a mold for making a rubber template with slits narrow enough to confine single strands of elongated DNA.

The new technique is akin to threading a microscopic needle with a thread of DNA, explains Juan de Pablo, a UW-Madison professor of biomedical engineering and a
'"/>

Contact: David C. Schwartz
dcschwartz@wisc.edu
608-265-0546
University of Wisconsin-Madison
8-Feb-2007