com dot Jankowski Tito + DIYbio

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People touch crosswalks.

But how will those species compare if we sample one button in San Francisco, CA and one in Boston, MA?

Ingredients:

Sterile swab
Plastic tube
Detergent

Instructions:
Dip the swab in the detergent. Wipe the swab on a crosswalk button, picking up lots of bacteria. Put it in the tube.

The detergent explodes the cells, and their DNA is released. So, now we have millions of genomes floating around, likely from dozens of different species.

Now, it would be nice if we could just sequence this as is.

Any we can. Kind of. Current computational tools can be used to sequence dozens of different species in the same mixture, as was shown when Craig Venter sequenced the ocean. So, we don’t need to separate the DNA into different species first. Great!

But we’ll need pure DNA first. That involves purifying the solution, removing the detergent, and possibly amplifying (making lots of copies) of our DNA so that we have enough to put in a Sequencer.

Ok, done. The bill is $15,000.

There’s a catch. 454, a Sequencing company, charges $15,000 to sequence 300 samples at once. We only sequenced 1 sample, but paid for 300. (Actually, this doesn’t make sense, will clarify later 11/30/08)

So let’s take a few more samples and get our friends in other cities involved. Get 300 different crosswalk samples, and now we’re talking about $50 instead ($15k/300).

That’s doable. That’s all courtesy of the mind of Jason Bobe.

Now what do you do with all the data? Is there something you’d rather sequence than crosswalks? Something that would be useful to compare with 299 other samples? This is what I’m interested in. Crosswalks were chosen because they’re easy, public, and have a distinct, mappable location.

Think on these things.