Synthetic biology seeks to design and construct biological components that can be modeled, understood, tuned to meet specific criteria, and assembled into larger integrated systems that solve specific problems. Such capabilities could transform biology in the way that integrated-circuit design transformed computing. Researchers could redesign enzymes, genetic circuits, and cells to their specifications, or even build biological systems from scratch.

Scientists have already made significant strides toward engineering microörganisms that produce ethanol, bulk chemicals, and drugs from inexpensive starting materials (see "From the Labs"). The work has been slow, however, in large part because engineers lack the tools to easily and predictably reprogram existing systems, let alone build new ones.