KATHERINE AULL's laboratory in Cambridge, Massachusetts, lacks a few mod cons. "Down here I have a thermocycler I bought on eBay for 59 bucks," she says, pulling out a large, box-shaped device she uses to copy short strands of DNA. "The rest is just home brew," she adds, pointing to a centrifuge made out of a power drill and plastic food container, and a styrofoam incubator warmed with a heating pad normally used in terrariums.