Air is full of DNA

(nature.com)

98 points | by howrude 3 days ago ago

14 comments

  • azalemeth 2 hours ago ago

    I do often wonder about stories like this in the context of forensic science – my (incomplete!) understanding a lot of the time suspect DNA samples are taken from small areas and amplified significantly with high-cycle count PCR. I'd worry that any jury presented with a statistical argument about a fragment of somebody's DNA being very unlikely ("1 in 100 million") to be different to the sample found at the scene would not be aware of all of the potential systematic reasons why the actual true probability may be much, much higher.

    • Terr_ an hour ago ago

      Probability seems to be one of those things humans habitually mess-up at.

      "The chances of this person's unique DNA showing up at the scene are a zillion to one!"

      "What does that really mean when the sample also contains unique DNA for a hundred other people? Did all of them commit the crime as a group?"

  • nelox 12 minutes ago ago

    What a wonderful title, a breath of fresh air.

  • butvacuum 2 days ago ago

    buried the lede, imho: we have enough DNA profiles to match their sampling up with.

    I'm always stunned when reminded that a full genome sequencing has gone from Human Genome Project's extreme cost and (edit: glacial) speed to using seqencing as the easy button.

    I hear we've also got machines that'll seqence, fit on a bench, and cost high five/low six figures. They've got issues to work out still though- iirc something about damaged sections causing issues.

    • cmrx64 2 days ago ago

      four figures these days. fits in your hand. nanopore is a revolution. https://nanoporetech.com/products/sequence/minion

      there’s youtubers that have videos about doing this in a home wetlab. very achievable. some amateur soil biologists using this to try and sample microdiversity as the planet… humanifies.

    • smolder 2 hours ago ago

      Paleontology has been really helped by the ease of sequencing, to the point where many evolutionary arguments are moot. Humans are apes, birds are dinosaurs. Some people still dispute it, but not with evidence on their side.

    • globular-toast 2 hours ago ago

      Should be noted, though, the cheaper/quicker techniques do still come with compromises compared to the "gold standard" technique used for the Human Genome Project.

  • seydor 2 hours ago ago

    Let's wait for smartphones with nanopores

  • madaxe_again 3 hours ago ago

    I was chatting with a biologist friend a while back, and one tidbit he dropped in was that any sample of air from anywhere on earth will likely contain the dna of organisms unknown to science, so abundant the tree of life is.

    • scotty79 4 minutes ago ago

      I firmly believe that there are thousands of times more species of viruses in circulation that influence human health, almost always in minor fashion, than we currently know. Any random, sub-clinical symptom is in my belief highly likely to be caused by one of such viruses.

  • dang 4 hours ago ago

    [stub for offtopicness]