Carbon nanotubes show promise for high-speed genetic sequencing

[n2doc]

Published: Thursday, December 31, 2009 - 15:36 in Physics & Chemistry

Faster sequencing of DNA holds enormous potential for biology and medicine, particularly for personalized diagnosis and customized treatment based on each individual's genomic makeup. At present however, sequencing technology remains cumbersome and cost prohibitive for most clinical applications, though this may be changing, thanks to a range of innovative new techniques. In the current issue of Science, Stuart Lindsay, director of Arizona State University's Center for Single Molecule Biophysics at the Biodesign Institute, along with his colleagues, demonstrates the potential of one such method in which a single-stranded ribbon of DNA is threaded through a carbon nanotube, producing voltage spikes that provide information about the passage of DNA bases as they pass through the tube—a process known as translocation.

Carbon nanotubes are versatile, cylindrical structures used in nanotechnology, electronics, optics and other fields of materials science. They are composed of carbon allotropes—varied arrangements of carbon atoms, exhibiting unique properties of strength and electrical conductivity.

Traditional methods for reading the genetic script, made up of four nucleotide bases, adenine, thymine, cytosine and guanine (labeled A,T,C,&G), typically rely on shredding the DNA molecule into hundreds of thousands of pieces, reading these abbreviated sections and finally, reconstructing the full genetic sequence with the aid of massive computing power. A decade ago, the first human genome—a sequence of over 3 billion chemical base pairs—was successfully decoded, in a biological tour de force. The undertaking required around 11 years of painstaking effort at a cost of $1 billion dollars. In addition to the laboriousness of existing techniques, accuracy is compromised, with errors accumulating in proportion to the number of fragments to be read.

more:
http://esciencenews.com/articles/2009/12/31/carbon.nanotubes.show.promise.high.speed.genetic.sequencing

[sharp_stick]

1. Faster sequencing?

I must really be getting old. When I was an undergrad we still used P32 gels to sequence DNA and a single gene could get you a publication. Now, you'd better have a freaking genome if you want a paper.

[mike_c]

2. P32 and huge hand poured polyacrylamide gels....

And DNA stains like DAPI. Now, in my mid-fifties, I'm starting to be a bit afraid every time I find a lump, mole, polyp, or soft-tissue twinge.

One night in grad school, when I was alone in the lab waiting for a gel to run or something, I picked up the old and mostly unused Geiger counter that sat under the scintillation counter, and just for jollies walked around the lab with it. Scarred the hell out of me and the next day the radiation safety folks had the whole place cordoned off for a clean up. The door handle to the -80 freezer was one of the hottest spots in the lab. Luckily it was almost all P³² and no isotopes like hot iodine.