"Johns Hopkins scientists have engineered cells that behave like AND and OR Boolean logic gates, producing an output based on one or more unique inputs. This feat, published in the May issue of Nature Chemical Biology, could eventually help researchers create computers that use cells as tiny circuits. (...) Many researchers are striving to mimic devices in everyday use by engineering new qualities into biological materials, including biomolecules and cells. Several of those engaged in this relatively new field, known as synthetic biology, have tried to create biological computers. At the heart of both the biological and the more everyday silicon-based variety of computers are Boolean logic gates, which produce responses that vary depending on what type and how many inputs they receive. For example, AND gates need two unique inputs to generate an output. In contrast, OR gates generate an output based on whether they receive one input, or another, or both. (...) "People like to have speedy computation," Inoue says. "We were hoping to achieve computation in cells on the order of seconds, which is significantly faster than what people have achieved thus far." To accomplish their goal, the researchers used a technique called chemically inducible dimerization, or CID. This tool takes advantage of natural biological mechanisms that bring together two proteins into a complex in the presence of a chemical." - Amira from Bookmarklet