The technique, made possible by the ability of nanofabrication to produce a microchip with light-impeding holes with a diameter one-tenth of the wavelength of light, could promise a new method of DNA sequencing by which the genetic code can be "read" from a single DNA molecule.
It also promises to aid in future drug discovery because "it provides a very powerful way of looking at fluctuations and variability in behavior of individual enzyme molecules. We are seeing those variations, and they are huge," says Watt Webb, professor of applied and engineering physics at Cornell. "Observing them with such detail was hardly accessible until this experiment."
The Webb group's report on watching individual molecules at work, "Zero-Mode Waveguides for Single-Molecule Analysis at High Concentrations," appears in the latest issue of the journal Science (Jan. 31, 2003). The article, which is illustrated on the cover of Science, also is authored by Cornell researchers Michael Levene, an optics specialist and postdoctoral associate in applied and engineering physics; Jonas Korlach, a biologist who is a graduate student in biochemistry, molecular and cell biology; and Stephen Turner, a nanofabrication specialist and former postdoctoral associate. Other Cornell researchers involved are postdoctoral associate Mathieu Foquet and applied and engineering physics professor Harold Craighead.
Until now, researchers were constrained from seeing individual molecules of an enzyme (a complex protein) interacting with other molecules under a microscope at relatively high physiological concentrations their natural environment by the wavelength of light, which lim
Contact: David Brand
Cornell University News Service