>PHYSICS NEWS UPDATE
>The American Institute of Physics Bulletin of Physics News
>Number 352 December 22, 1997 by Phillip F. Schewe and Ben
>Stein
>
>ATTACHING A SINGLE DNA MOLECULE TO A SILICON
>SURFACE can now be done with heat instead of chemicals (which
>are usually specific to certain surfaces or sites), promising a more
>general and powerful method for depositing single DNA molecules
>onto specific locations on silicon chips. Such "DNA chips" are
>expected to provide a new approach to developing bio-sensors or
>bio-electronic circuitry. Researchers at Rockefeller University
>(G.V. Shivashankar, shiva@athena.rockefeller.edu, phone 212-327-
>8160) first attach a single DNA molecule to a latex bead in water.
>They then use a focused laser beam known as an "optical tweezer"
>to trap the bead and hold the DNA molecule in place. Next an
>atomic force microscope tip comes in contact with the bead.
>Meanwhile, the laser stays on in order to attach the bead to the
>probe tip. The composite tweezer-and-AFM tool allows great
>manipulation flexibility, retains the biological functionality of the
>DNA, and offers the possibility of studying DNA and protein
>interactions (Applied Physics Letters, 22 Dec 1997).
>
Max More, Ph.D.
more@extropy.org
http://www.primenet.com/~maxmore
President, Extropy Institute: exi-info@extropy.org, http://www.extropy.org