By linking a series of protein switches, researchers made prototype cell-level counters that could eventually be used to coordinate complex sets of genetic instructions running on biomolecular machines, from disease-hunting cells to intracellular computing networks. In the electronic world, basic counting functions underlie even the most powerful supercomputers.

“What we’ve done is to impose some of the controls we’ve imposed in electrical engineering onto the biological cell,” said synthetic biologist Timothy Lu at the Massachusetts Institute of Technology. “We hope to be able to control the cell more reliably, and have it perform more defined functions. This forms the fundamental basis for building more complicated circuits.”