dna-1A year after creating organisms that use a genetic code different from every other living thing, two teams of scientists have achieved another “synthetic biology” milestone: They created bacteria that cannot survive without a specific manmade chemical, potentially overcoming a major obstacle to wider use of genetically modified organisms (GMOs). The advance, reported on Wednesday in Nature, offers what one scientist calls a “genetic firewall” to achieve biocontainment, a means of insuring that GMOs cannot live outside a lab or other confined environment. Although the two labs accomplished this in bacteria, “there is no fundamental barrier” to applying the technique to plants and animals, Harvard Medical School biologist George Church, who led one of the studies, told reporters. “I think we are moving in (that) direction.” More