I asked the woman at the biotech trade display what the little microwave-size machine did. "It's a PCR machine," she said, beginning to demonstrate. She opened a lid to expose a grid of small wells in the heart of the machine. "Put your samples in there, close the lid, punch in the numbers, and wait."

So simple even a child could do it, provided the child has the $7,000 currently needed to buy the machine. This is now all it takes to clone DNA. (Cloning simply means making multiple identical copies, whether of genes, molecules, cells, or whole organisms.) Starting with a sample of as little as a single fragment of DNA, the automated process can produce a million identical fragments in only a couple of hours; you can get a billion if you wait another hour.

The woman had no doubt that sensitive and accurate DNA copiers like this have an assured future. "They'll soon be in doctor's offices to test for diseases," she said.