ananyo writes "Synthetic biologists have developed DNA modules that perform logic operations in bacteria. These 'genetic circuits' could, for example, be used by scientists to track key moments in a cell's life or, in biotechnology, to turn on production of a drug at the flick of a chemical switch. The researchers have encoded 16 logic gates in modules of DNA and stored the results of logical operations. The different logic gates can be assembled into a wide variety of circuits."