Shrinking 'laboratory' onto a computer chip.

Laboratory technicians soon may be trading their lab coats for laptop computers. Fred Regnier, professor of chemistry, Purdue University, West Lafayette, Ind., has developed a way to take specialized instruments from the chemistry lab, shrink them 1,000 to 1,000,000 times, and put them on a computer chip. This will allow scientists to pack dozens or hundreds of "laboratories"--each fully capable of carrying out complex chemical analyses--on a single silicon chip, reducing the cost and boosting the efficiency of many chemical and medical analyses.

The miniature laboratories can be used to separate mixtures into pure chemical components. Such separations, called capillary chromatography and capillary electrophoresis, frequently are used in clinical analyses of blood and tissue samples, medical research, and drug discovery. In standard chromatography, a solution to be separated is poured through a tube or column packed with various particles coated with a chemical compound. The various components of the solution are attracted to the particles with different affinity. As the mixture flows through the column, it separates into a series of zones, each containing a pure substance.

The miniature laboratories employ the same principle. The difference is in their size and the way they are made. Channels and microscopic "particles" are created using photolithography and chemical etching, the same technologies utilized to build semiconductors. The entire laboratory--with chemical reaction vessels the size of a speck of dust and chromatography columns the size of a human hair--is cut from a single piece of silicon, similar to the creation of a sculpture. Liquids are moved on the chip by voltage applied at the ends of the...