Techniques normally applied in the semiconductor industry are finding an increasing number of uses in biological research. In one recent application, a team of researchers from the California Institute of Technology has built a microfabricated device to measure the size of single DNA molecules (H Chou et al. 1999 Proc. Nat. Acad. Sci. 96 11).
It works by having a dilute solution containing DNA molecules flow along a network of channels (see figure). The individual DNA molecules are visualized with the aid of a fluorescent dye that binds very tightly to double-stranded DNA. The researchers determined the size of the molecules by measuring the integrated fluorescence intensity as they flowed through the microfabricated channels.
In the April issue of Physics World, Bob Austin from Princeton University, US describes why this technique may have the same impact on microbiology as the integrated circuit did on the world of electronics and computers.