Today’s Test Tubes

Picture that icon of science, the test tube. Now forget it-or at least envision it as a vastly smaller and differently shaped vessel that is leading to a much faster, more organized, and less expensive way to develop drugs, agrichemicals, and advanced materials.

The square-inch grid shown here contains 128 troughs-new-wave test tubes-filled with varying combinations of metallic oxides that scientists examined for their ability to form high-temperature superconductors. A research team at the Lawrence Berkeley National Laboratory, led by physicist Xiao-Dong Xiang and chemist Peter Schultz, used a gun-like mechanism to deposit the chemicals. After applying heat to mix and stabilize them, the scientists lowered a plate with 128 probes to test which compounds showed negligible electrical resistance at certain temperatures-an indication of potential superconductivity.

In a process known as combinatorial chemistry, scientists are using such grids to assemble and evaluate large numbers of permutations of compounds at one time. To continue their research, for example, Xiang and his colleagues created one-inch grids with 1,024 troughs earlier this year.

This photograph, which shows molecular combinations diffracting light like paints in a miniature watercolor palette, was taken by Felice Frankel, artist-in-residence at MIT’s Edgerton Center. Her forthcoming book On the Surface of Things (Chronicle Books, 1997) will include a similar image, among many other photographs, and text by George Whitesides, a Harvard University professor of chemistry.