Synthetic biologists string genes into living machines
In the 30 years or so since its inception, genetic engineering has created quite a legacy, ranging from glow-in-the-dark bunnies to bacteria that churn out life-saving drugs. This now-common lab technique gave biologists their first taste of custom designing living things by tinkering directly with their genomes. But for all its utility, genetic engineering hasn't met scientists' most optimistic expectations. Because the enzymes that slice and splice DNA aren't entirely predictable, swapping out an organism's genes can be a hit-or-miss prospect.