“Kill switches” shut down engineered bacteria
Many research teams are developing genetically modified bacteria that could one day travel around parts of the human body, diagnosing and even treating infection. The bugs could also be used to monitor toxins in rivers or to improve crop fertilization. However, before such bacteria can be safely let loose, scientists will need to find a way to prevent them from escaping into the wider environment, where they might grow and cause harm. To this end, researchers at MIT, the Broad Institute of MIT and Harvard, and the Wyss Institute at Harvard University have developed safeguards in the form of two so-called “kill switches,” which can cause the synthetic bacteria to die without the presence of certain chemicals. In a paper published this week in the journal Nature Chemical Biology, the researchers describe their two kill switches, which they call “Deadman” and “Passcode.” Stand-alone circuits There have been a number of attempts to develop kill switches...