DNA Sequencer to Space?

Even now, researchers at several institutions are experimenting with a faux-DNA material, dubbed XNA (xeno nucleic acid).

This is a synthetic version of DNA that uses the same bases as DNA (adenine, cytosine, guanine and thymine) but has them attached to sugars that are different from the ones we see in DNA.

Clean it up

Beyond searching for alien life, the MinION will also be used to evaluate the ISS environment and crew.

As much as NASA tries to make sure everything is spic-and-span before sending a delivery to the station, microbes are inevitable.

“We try to put things up there as microbially clean as possible, but we don’t sterilize the crew, of course,” said Wallace. “So, they take their microbiome and that becomes the ISS microbiome.”

Her lab already does quarterly microbial monitoring of the surfaces and air of the ISS.

The water is sampled once a month because it’s made of recycled urine and condensate, which includes sweat and exhaled breath. This recycling process increases the likelihood that the crew could ingest potential pathogens.

In the past, they’ve found the kinds of microbes that are expected around humans, including,

  • Staphylococcus aureus
  • Pseudomonas
  • Streptococcus
  • Klebsiella

Wallace also mentioned that a cloth-like wall in the Russian section of the ISS once grew green and fuzzy from astronaut’s bungee-ing their wet towels to it in order to dry.

To battle grime or illness on the ISS, NASA supplies and resupplies a wide variety of antibiotics, disinfectants and biocides; but the best method of attack isn’t known until a sample of the problem-causing microbe is analyzed.

Currently, all of the samples taken from the environment and the occupants of the ISS have to be stored and then sent back to Earth for sequencing.

The hope is that MinION will allow these samples to the sequenced in real time. This will eliminate the need for long-term storage of samples, which Burton said would be implausible for an extended mission, such as a proposed 500-day journey to Mars.

Being able to sequence samples immediately to identify causes of disease or uncleanliness will also provide NASA with valuable information about the kinds of microbes these future missions should anticipate.

With the limited space that comes with extended missions as well as the necessary supplies required for such journeys, everything that’s brought along needs to have a purpose.

No adjustments were made to the MinION for use in zero gravity, but Sarah Wallace said they did optimize the protocols for use in order to cut down on the time the crew would need to spend on this work.

The lack of modifications to MinION means that even the simplest of lessons learned during this experiment can have effects that go beyond the space program.

“If we can make something work on the ISS, in microgravity, then, any changes or advances we have to make to work it there have benefits on Earth as well,” said Burton.

Lessons learned in space may also translate into knowledge for other “low-resource” environments, where resources are limited.

Researchers have already used the MinION in Liberia for rapid sequencing of Ebola.

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Ragnar Larsen