A few (very) small bits and pieces

(via BBGM) There's an interesting paper about carbon nanotubes wrapped in DNA being used as sensors in living cells in Science this week (subscription required). Carbon nanotubes are tiny - as the name might suggest - cylindrical carbon molecules that are incredibly strong. Amongst other things they also display distinctive near-infrared photoluminescence when in aqueous solution.

Researchers at the University of Illinois wrapped particular double stranded oligonucleotides around the nanotubes. When exposed to certain ions the negative charges along the DNA backbone get neutralized and the oligonucleotide shifts from B to Z form, which decreases the nanotube's near-infrared emission energy: these changes can be readily detected.

'This is really one of the most imaginative applications of nanotubes in the life sciences arena,' said Tobias Hertel, a physical chemist at Vanderbilt University in Nashville.

These nanotube sensors are cool because they work in "strongly scattering or absorbing media" - they were tested in blood, black ink and living mammalian cells and tissues. So far the authors have used oligonucleotides sensitive to mercury ions, but the hope is that eventually the sensors will be able to detect small drugs or chemicals associated with different diseases, like cancers (a new scientific discovery pitched as helping to cure cancer? Novel PR approach). Other fluorescent dyes used to tag molecules in experiments aren't very stable when exposed to light: nanotubes are. They're also less toxic than quantum dots, another possible nanotech sensor technology.

Moving swiftly on: the second neat thing I read today was (via Boing Boing) about a Dance Dance Revolution like game (for the uninitiated: it's this big floormat with pressure sensors on it which you dance on in time to music played by a games console) in which you build strings of DNA. It's called "Codon Hoedown" and it's part of the Sea of Genes exhibit at the Birch Aquarium in La Jolla, California. Tying in loosely with an earlier post, Sea of Genes is funded by a grant by the National Science Foundation to Brian Palenik and Ian Paulsen at TIGR. Yes, it's Venter again. There is no escape (at least not on this blog, seemingly).