Number 394 (Story #3), October 1, 1998 by Phillip F. Schewe and Ben Stein|
DNA-MEMBRANE SELF-ASSEMBLIES, materials formed by mixing DNA molecules with artificial versions of the membranes that form the protective coverings of cells, are highly organized at length scales from nanometers to microns, new experiments have confirmed. These materials, currently serving as gene delivery vehicles, are made of layers consisting of rows of equally spaced, single DNA molecules alternating with sheets of membrane. Using a 1-by-4 micron x-ray beam at the Advanced Photon Source in Argonne National Lab, a UC Santa Barbara-Argonne team showed that the molecules in these materials are aligned over length scales of microns. The spaces between molecules form organized arrays of "nanopores" which have many possible chemical applications. In addition, these materials can potentially serve as templates for the fabrication of inorganic nanostructures with geometries and features that were previously impossible to achieve. (G. Wong et al., Applied Physics Letters, October 5, 1998; J. Radler et al., Science, 7 February 1997; also see figure at Physics News Graphics.