Friday, September 28, 2007

A little follow-up

Sometimes soon after writing something I see something related to the post, but I've been lousy about doing anything about it. But this week, particularly with a desire to recognize the generosity of friends & strangers, I will.

  • Following my mention of the Cambridgeport chickens, the Boston Globe mentioned some more free-range biotechophilic poultry: there is a wild turkey living near Kendall Square in the vicinity of Biogen Idec. I've seen one gobbler down near North Station, but never there -- which is mildly irritating since used to walk through there a lot. I'm also reminded of the flock of enormous feral white geese that hang out down by my old haunt of 640 Memorial Drive, though for some reason they don't stir much affection from me (though they have some very passionate defenders every time the parks department suggests thinning the flock)

  • One of our summer interns stopped by for a visit & with a grin announced she had a present for me. I was quite mystified -- and then startled & thrilled to see the nanopore paper in her hands
  • . The paper is more review & overview & planning/dreams than data, but it's hard not to get a little caught up in the enthusiasm. Imagine getting 200 nt/s from nanopores packed in at nearly micron spacing! The article itself doesn't expand much on the process of transforming the sequence into a different defined sequence (with each nucleotide translated into words of multiple nucleotides), but does explore a bit more why this would be useful -- to generate more widely spaced signals -- in a sense, the nanopores just read too quickly. However, it does mention the company (Lingvitae AS) with the technology, and they have some slick animations. The details are a bit sketchy, but with a mention of TypeIIS restriction enzymes (those that cleave outside their recognition site), ligation and the fact that the new words are added at the opposite end, one can make some guesses about how it works -- probably involving circularlization. It does sound like you aren't going to get the super-long reads once dreamed about for nanopores, as there isn't talk of long sequences being transliterated into even longer ones, but if you really could get the throughput & have nanopores grabbing new DNA molecules after they finished with old ones, it is possible to imagine getting really amazing sequencing depth.
  • A reader was kind enough to use a comment to point out another article on the new Genome Corp, and indeed showing a bit more conscious connection to the original. The article is still spotty on details, but does have two tidbits. First, is a strong hit that electrophoretic separation is still in play here -- but presumably on a very micro scale -- perhaps on-chip? Second, Ulmer wants to set up a very highly optimized DNA factory, not a company selling machines or kits. Pondering different genome sequencing business models is at least a post in itself, but since I currently work in a highly industrialized DNA factory it does hold some resonance

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