Extracting DNA from the air – DNA evidence of human occupancy in indoor premises

At work we do this with DNA floating around in the ocean (have to track down all those nasty invasive crabs) but I wouldn’t have guessed we could do this with the air around us as well. That’s so cool.

Maybe we should spin up an air-based version for the office to keep track of who’s in coming to work the most

Do you think this would become doable by private citizens in the near future for a reasonable amount of money? I've been curious about how far upstream the sculpins are in our local streams. I've seen some in pretty small streams but looking for them typically involves standing still in very cold water for long enough to see them move.

I’m not sure! Because the water would move the dna relatively quickly it could be hard to get good results at the higher ends of their range. And I’m not sure about costs, but I’ll look into it.

One strategy that might work, though you’d need to take care and get permission: create a barrier to downstream so sculpins can’t come upstream, and place a trap above the barrier and see if any enter the trap after a few hours. That should tell you if they’re occupying that part of the stream. Just sticks with a mesh net placed as a barrier should be sufficient to prevent any downstream occupants from coming up and entering the trap.

Another would be to place a camera in the water and review the footage. I use this approach with an iPhone 15 Pro (I just stick it straight in the stream) and I get excellent results. There are always really cool animals popping up. Here’s an example: https://youtu.be/N9PLra7amfs?si=kZ01cFZ8upKLxNPb

This was in a very tiny puddle off the side of a creek in summer. At a glance it appeared empty, but after putting the camera in and walking away for 10 minutes or so, all kinds of creatures like this sticklebacks came out of the detritus.

Thanks. I guess I was thinking about looking to see if there is dna from upstream passing by. At some point I'd guess it is hard to tell if there are fish upstream but I'm not sure how to think about what factors are important. On the other hand just looking at streams isn't the worst thing to do.

I don't think my own curiosity is a good enough reason to build a trap or barrier. But a camera is a good idea. I actually just picked up some parts from blue robotics to put together a setup for one or more cameras using some stuff I have laying around.

Cool sticklebacks! One of the places I stumbled on Sculpins was in the Taylor River on Vancouver island. I saw something moving and nearly froze myself staying in until I found several of them.