Hunting for DNA in space
Given that DNA sequencers are now small enough to take into space, can we use them to hunt for alien DNA? NASA's Aaron Burton spoke to Chris Smith about whether you can look for DNA in space...
Aaron - Actually, we're sequencing DNA in space right now on the International Space Station.
Chris - Terrific. Why?
Aaron - It kinda depends on who you ask. Our team has microbiologists, infectious disease experts and also some astrobiologists. For the crew health standpoint, if you have a sequencer you can identify microbes in air, surfaces, and water and make sure that everything's safe. And also, if a crew member shows signs of illness, then you can diagnose the disease that they have and determine the appropriate treatment, so if they need antimicrobials or if an infection will go away on its own.
Chris - And actually the process of DNA sequencing, "it doesn't mind" being in microgravity such as the international space station - it doesn't affect the process?
Aaron - So far it hasn't. We weren't really concerned about the nanopores themselves, and the mechanism for sequencing and passing the DNA through. The bigger question was whether the flow cells can survive the launch vibrations and shock just to get up to the space station. And then whether or not the crew members themselves would be able to move the fluids around and load the flow cell without introducing air bubbles. But we're eight experiments in and things are going great.
Chris - Well that's very encouraging. Now returning to the question the student asked: could we, or would there be virtue in taking a device like this to a place like Mars and looking for vestiges of DNA in space? Because Matt Powner's saying that the same chemistry applies across the universe, therefore it's likely we might be meeting aliens that use the same sorts of genetic heritable material like DNA that we do.
Aaron - Yeah. So I would agree with that from the fundamental chemistry level. And we also know we have meteorites from Mars that have landed on Earth, so we know that material from Mars can make it to Earth. And then we have also sent a number of spacecraft from Earth to Mars so we know that we have sent a few microbes attached to those spacecraft. So there's a good reason to think, at least in these kind of events, you transfer organisms from Earth to Mars and visa versa.
Chris - So there's reason to suspect we might find DNA. But what about alien DNA and if they don't use DNA DNA, like we do but they have something similar, could you use the same sort of platform or technology to go hunting for that instead?
Aaron - Yeah, that's one of the really intriguing things about the nanopore sensor is because you're actually analysing the molecule directly when it's going through the nanopore, you can measure a whole lot of things. So not just DNA but people have shown you can directly sequence RNA, and even proteins that they've actually passed through these pores.
So you can imagine that if you had alien life that used a different alphabet you would still be able to pass those molecules through the nanopore and get that current change that would be diagnostic of an informational molecule going through it.