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 Instead, Rubins pushed for carefully controlled experiments with a
mix of a bacteria, a common virus and mouse cells, all already
repeatedly sequenced and safe for testing in the space station's
closed-loop environment.
Rubins, a trained microbiologist who arrived at the space station on
Saturday, will be using the samples to put Oxford Nanopore's MinION
sequencer - a pocket-sized DNA sequencer - through its paces.
The tests are intended to prove whether the technology can be used
to understand microbes in the space station, to scan fellow
astronauts for genetic changes that could diagnose illness, and in
future missions, potentially to test samples from Mars and elsewhere
for signs of DNA-based life.
One of the first things the scientists need to prove is just how
well the machine operates in microgravity. "Technology behaves
differently up here. Fluids behave differently up here,” Rubins said
in an interview with Reuters on Thursday from the International
Space Station.
The MinION sequencer, which is about half the size of a smartphone,
operates fundamentally differently from current DNA sequencers, said
Sarah Wallace, a microbiologist at the National Aeronautics and
Space Administration's Johnson Space Center in Houston.
With most sequencers, scientists put in a sample and it runs for 24
to 48 hours, then stops. The station's sequencer displays its
analysis as it works.
"Within minutes of loading your sample, you're starting to get the
sequence data back ... so how long it runs is based on the
scientific question you’re asking," Wallace said.
The MinION DNA sequencer is among the nearly 4,900 pounds (2,223 kg)
of cargo scheduled to be launched to the station on Monday aboard a
SpaceX Dragon capsule.
It will be the first use of the machine in space, Wallace said in a
news briefing on Wednesday.
Currently, samples from space must be frozen and flown back to Earth
for analysis.
"We don't get to analyze everything that is happening to human
beings and to cells in real time," Rubins said.
In the future, Rubins would like to use the DNA sequencer to learn
more about potential colonies of microbes that have taken up
residence in the station's water system and elsewhere aboard the
orbiting laboratory.
“We've got wonderful clean water, but we've got a water system
that’s been up here for 15 years. Do we have any microbes living in
the system?" Rubins said.
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If all checks out, the DNA sequencer could be used to help diagnose
illness in astronauts on the space station and understand whether
any disease-causing microbes are susceptible to antibiotics, helping
to conserve valuable medications that cannot be readily restocked.
The device joins a suite of other diagnostic instruments aboard the
station, including a polymerase chain reaction, or PCR, device that
can test single genes.
"These kinds of small, portable genomic technologies are going to
let us look, in real time, at what's actually happening to bone
degradation, for example. What's happening to your immune system,
what's happening to a population of microbes that you bring up in a
culture flask?" Rubins said.
Testing the DNA sequencer in space also could pave the way for its
use in remote or resource-poor areas on Earth.
"This kind of device is something you would use in the developing
world, you could use this in an outbreak situation, you could use
this in a clinic where you don't have a lot of resources to buy a
full-scale sequencer but you can enable some kinds of diagnostic
tests in really resource-poor settings," Rubins said.
Rubins said the space station is an "amazing place" to test device
performance when power and data processing capabilities are limited.
"We have to engineer devices that are going to work in space
stations. Those same things are going to work in the most remote
regions on Earth,” Rubins said.
(Reporting by Julie Steenhuysen; Editing by Jonathan Oatis)
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