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Air is full of DNA

nature.com

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Re: Air is full of DNA

#31

Post by robertlagrant »

cmrx64 wrote: post #3
butvacuum wrote: post #2

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 somethin…

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.

Ex-Nanopore employee here. One interesting thing we heard about internally was that OceanX[0] has one of our GridION[1] devices (slightly larger, and built-in compute) that they were using to track whales in the ocean by sequencing DNA found in seawater. Really cool.

[0] https://en.wikipedia.org/wiki/OceanX

[1] https://nanoporetech.com/products/sequence/gridion

Re: Air is full of DNA

#32

Post by [deleted] »

smolder wrote: post #15
butvacuum wrote: post #2

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 somethin…

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.

[deleted]

Re: Air is full of DNA

#33

Post by chiph »

Terr_ wrote: post #20
azalemeth wrote: post #19

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 wou…

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?"

Depends on how they're using it. To find an unknown person and prove they were at a scene - yeah you'll have the 100 person's worth of DNA to sort through and then match against a (presently) incomplete DNA database. But if you already have a suspect and need to place them at the scene, if their DNA is one of the 100 then they have shown that.

Re: Air is full of DNA

#34

Post by ch4s3 »

chiph wrote: post #33
Terr_ wrote: post #20

Earlier quoted context omitted.

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?"

Depends on how they're using it. To find an unknown person and prove they were at a scene - yeah you'll have the 100 person's worth of DNA to sort through and then match against a (presently) incomplete DNA database. But if you already have a suspect and need to place them at the scene, if their DNA is one of the 100 then they have shown that.

But we’re they at the scene or did they just bump into someone or something that was there?

Re: Air is full of DNA

#35

Post by chiph »

ch4s3 wrote: post #34
chiph wrote: post #33

Earlier quoted context omitted.

Depends on how they're using it. To find an unknown person and prove they were at a scene - yeah you'll have the 100 person's worth of DNA to sort through and then match against a (presently) incomplete DNA database. But if you already have a suspect and need to place them at the scene, if their DNA is one of the 100 then they have shown that.

But we’re they at the scene or did they just bump into someone or something that was there?

That's something that would have to be addressed at the trial by the defense attorney raising challenges.

If the DNA is present, it's present - barring any procedural mistakes by the forensics technicians (mislabeled sample, dirty lab equipment, didn't follow manufacturers instructions, etc). Or deceit by one or more members of the forensics team to implicate the suspect.

Re: Air is full of DNA

#36

Post by mpaepper »

pfdietz wrote: post #27
smolder wrote: post #15

Earlier quoted context omitted.

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.

> birds are dinosaurs Not that I doubt that, but how does DNA help, when we have no DNA samples from dinosaurs?

https://www.syfy.com/syfy-wire/scientists-discover-well-pres...

Re: Air is full of DNA

#38

Post by etiam »

gus_massa wrote: post #30
dkobia wrote: post #24

This always blows my mind. We are currently breathing in the DNA of the trees, animals, and people around us—and we’re leaving ours behind for them, too. We’re all one big genetic soup.

The immune system destroy all the DNA in unexpected places in case it's a https://en.wikipedia.org/wiki/Viroid or something. Better safe than sorry. One of the important steps in mRNA vaccines was to surround the mRNA with a lipid to ensure it can survive long enough to enter a cell. Naked mRNA would not have worked.

One has to wonder whether destroy is all it does though. Analyzing this as cues about the surroundings seems like it could be pretty useful for successful living, and something evolution could well pick up on. Will we find eventually that some of those nucleic acid fragments were being hauled off for identification in something like an extra inner sense of smell?

Re: Air is full of DNA

#39

Post by throe939rjdor »

gus_massa wrote: post #30
dkobia wrote: post #24

This always blows my mind. We are currently breathing in the DNA of the trees, animals, and people around us—and we’re leaving ours behind for them, too. We’re all one big genetic soup.

The immune system destroy all the DNA in unexpected places in case it's a https://en.wikipedia.org/wiki/Viroid or something. Better safe than sorry. One of the important steps in mRNA vaccines was to surround the mRNA with a lipid to ensure it can survive long enough to enter a cell. Naked mRNA would not have worked.

Not just rna, but dna as well.

Re: Air is full of DNA

#40

Post by the__alchemist »

cmrx64 wrote: post #3
butvacuum wrote: post #2

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 somethin…

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.

I have a mol bio home lab, and decided against it because while the devices themselves are reasonably priced, the flow cells are an expensive disposable.

I use Plasmidsaurus instead: Pay them $15/sample online, drop off the tubes in a styrophoam box labeled with a dinosaur in a nearby university building; get the results next morning. They use Oxford Nanopore, but are loading your sample along with many other samples to maximize flow cell use.

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