March 18, 2002

The Washington Post (online)

'DNA Computer' Masters Math

Scientists have used a "DNA computer" to solve the largest mathematical problem yet using the new technology.

DNA computers take advantage of the fact that the basic components of genetic material attach to one another according to strict rules -- rules that can be used to solve logic problems. While the devices are very primitive so far, researchers think they may eventually be able to create highly useful, extremely small "molecular" computers.

In the new research, Leonard Adelman of the University of Southern California in Los Angeles and colleagues used a DNA computer to solve a logic problem with 24 variables and 1 million possible solutions.

"For thousands of years, humans have tried to enhance their inherent computational abilities using manufactured devices," the researchers wrote in the March 14 Science. "But it was only with the advent of . . . the electronic computer some 60 years ago that a qualitative threshold seems to have been passed and problems of considerable difficulty could be solved. It appears that a molecular device has now been used to pass this qualitative threshold for a second time."