user posted image rIt's not your normal, electronic silicon-based machine, but scientists have made a computer from a small, circular piece of DNA, then inserted it into a living bacterial cell and unleashed the microbe to solve a mathematical sorting problem. "A computer is any system that can read some input and give some readable output," says Karmella Haynes, a biologist at Davidson College in North Carolina and co-author of a new study appearing in the Journal of Biological Engineering. Haynes and her team looked to harness the power of DNA recombination to solve the so-called "burnt pancake problem": a puzzle about how to stack different-size flapjacks that are burned on one side and perfectly cooked on the other using the fewest number of flips to arrange them so the largest are on the bottom and all are golden side up. "This work is the first work I've encountered which uses living cells in order to solve a specific computer science problem," says Tom Ran, a graduate student in the lab of computer scientist Ehud Shapiro at the Weizmann Institute in Rehovot, Israel. By showing that DNA functioning as a computer would be able to solve the burnt pancake problem, Haynes and her team demonstrated that if their system could be scaled-up, it could spit out answers to complex problems like the most efficient air routes between Chicago and Singapore or the best way to route phone calls around the U.S.—conundrums that companies like FedEx and AT&T have grappled with for years—in a fraction of the time that it takes conventional computers to do.

Researchers have envisioned using DNA computers for several other applications, such as a way to detect changes in live systems—like cancer within the body or the spread of contaminants in a lake. "DNA computers may be able to accomplish things that electronic computers cannot," says Len Adleman, a molecular scientist at the University of Southern California. "For example, it is very hard to conceive putting an electronic, silicon-based computer into a bacterial cell.

linked-image View: Full Article | Source: Scientific American