An article on nano-wires:

http://www.trnmag.com/Stories/2004/022504/...ief_022504.html

Nano-wires have been used to read DNA efficiently, and are apparently
able to work with samples that are much more sparse on DNA.

I've read about Nano-pore gene-sequencing devices being researched at
Caltech and elsewhere. How would these compare? Are they rival
techniques, or could they in some way be complementary to each other?

To the extent that one can tell from this puff-up press release (which,
like _all_ press-releases, is long on hype and short on information), this
technique is not even in the same ballpark as the "nanopore" technique,
but is merely an "electronically readable" form of oligonucleotide detection.
The "nanopore" technique, if it can be made to work, will allow sequential
reading of strands of DNA as if they were tape. This "nanowire" sensor
appears to only be able to determine whether a sample of DNA happens to
have a pre-specified three-character oligonucleotide somewhere along its
length, which makes it suitable for determining whether a particular DNA
"fingerprint" is present or absent in the sample, but not _where_ that oligo
occurs on the DNA sequence. And while it is _theoretically_ possible to
construct a massive array of sensors to detect all possible oligos of a
given length and to reconstruct the sequence from the set of oligos that
"light up," in practice, sequencing by oligos has never worked very well,
because the sequence reconstruction process is combinatorically difficult,
as it is equivalent to the NP-complete "Hamiltonian Circuit" problem.

Thanks again, Dr Pusch -- that's what I figured too, based on the
article. It seems like something comparable to the gene array chip
approach, but having greater sensitivity.

Btw, here's a recent blurb I read on Caltech and it's nanopore
program:

http://news.nanoapex.com/modules.php?name=...rticle&sid=4291

The nanopore thing seems to be the most promising for gene sequencing,
from what I've read.

I don't think the article mentioned this but the work was done by
leiber et al. They also have a few older review articles in Science.
Similar work was just published by a group at hewlet packard. I also
was just at a seminar addresing the reproducablity of the electrical
props. of nanowires and their dependance on contact area between the
source and drain of the device. I guess a lot of the older research
is being debunked in light of this problem.