The ability to extract trace bits of DNA from soil, water, and even air is revolutionizing science. But it's not foolproof. In the late 1980s, at a federal research facility in Pensacola, Florida, ...

Pierre Jorcin slides on a pair of gloves, attaches a plastic tube to a filter, plunges it into the water, presses the start button on a small pump and then slowly begins walking through the river ...