Scientists at Stanford University have engineered a basic form of transistor using bacterial DNA, potentially paving the way for more complex biological computing systems. In a paper published in the journal Science this week, the five researchers describe how they used special enzymes to control the flow of nucleic acids in E. coli bacteria, creating living versions of the key logic gates — AND, OR, XOR, etc. — that form the basis of computer programming languages.

"Any system that's receiving information, processing information, and then using that activity to control what happens next, you can think of as a computing system," researcher Drew Endy tells NPR. Potential uses of the new technique, which is still in its early stages, include the construction of living computers to fight disease: programmed effectively, a group of cells could detect the presence of cancer in the human body and change color to indicate the result. Unfortunately, unlike their electronic counterparts, biological transistors don't follow Moore's law of ever-decreasing size and ever-increasing efficiency — Endy warns that living circuits are unlikely ever to outperform a smartphone.