Materials scientists are becoming increasingly intrigued by the prospects of making compounds on a nanometer (one-billionth of a meter) scale. But finding reaction vessels small enough to hold those materials is tough. It turns out that nature may provide excellent nano-beakers. Even more remarkable: They're everywhere.

A team of scientists from Montana State University (MSU) in Bozeman and Temple University in Philadelphia, Pa., has emptied a virus of its infectious genetic matter and found that the harmless shell makes an excellent container for tiny amounts of materials. Virologist Mark Young of MSU and Temple chemist Trevor Douglas took a virus that infects black-eyed peas, spilled out its RNA, and filled the 18-nanometer-diameter cavity with tungstate ions that formed a crystal. "If you think of viruses as containers of incredibly well-defined sizes, you can pick the size you want," says Douglas. Viruses run 15 to 200 nanometers in diameter and generally come in the form of spheres or rods. What's more, the supply is limitless. Viruses reproduce themselves with remarkable size consistency, and are easily renewable.