The notion of using molecules as the working elements of a computer goes back several decades. It wasn’t until 1994, however, that anyone actually stepped into a laboratory and succeeded in solving a computational problem in a test tube.
That was when computer scientist Leonard M. Adleman of the University of Southern California, using techniques from molecular biology, manipulated strands of DNA to solve a mathematical problem: Given seven points linked by one-way paths, find a route that visits each point once on the way from a specified starting point to a given end point.