January 1, 1970 (Vol. , No. )
To some people, DNA looks for all the world like a cell’s electrical wiring (see also 1 and 2), so it’s not totally surprising then that researchers Colin Nuckolls, a professor of chemistry at Columbia University and Jacqueline Barton, a professor of chemistry at Caltech had an interest in studying the electrochemical properties of the double helix. After devising a means of attaching DNA to carbon nanotubes to precisely measure the flow of electrons through the former, they were able to demonstrate that DNA resisted current about the same as a piece of graphite of the same dimensions. Not surprisingly, if they cut the DNA with a restriction enzyme (thereby “cutting the wire”) and repeated the experiment, the flow of electrons stopped completely. More interesting, though, was what occurred when they introduced a single base mismatch in the DNA wire’s double helix – the resistance increased 300-fold, apparently due to the distortion of the double helix by the unpaired bases. Now the researchers are turning their attention to using their knowledge to develop new means of detecting single nucleotide polymorphisms (SNPs) electrically.