International Space Station "tricorder" sequences DNA in space for first time
/
Using the MinION, astronaut Kate Rubins sequenced DNA in space for the first time ever. Photo Credit: NASA
In a situation reminiscent of one on Star Trek, DNA was successfully sequenced on the International Space Station for the first time.
The Biomolecule Sequencer experiment, which was launched to the outpost via a SpaceX Dragon capsule in July 2016, was conducted by NASA astronaut and Expedition 48 flight engineer Kate Rubins. The investigation consisted of samples of mouse, virus and bacteria DNA and a candy-bar-sized hand-held device called MinION.
"Welcome to systems biology in space," said Rubins after the first few DNA samples were sequenced successfully.
The MinION DNA sequencer. Photo Credit: Oxford Nanopore Technologies
MinION is a tricorder-like commercially available DNA sequencing device developed by Oxford Nanopore Technologies. According to NASA, it works by sending a positive current through pores embedded in membranes called nanopores inside the device. At the same time, fluid that contains DNA samples pass through the device.
As individual DNA molecules begin to block the nanopores, they change the current running through the device in a way that is unique to a particular sequence. Researchers can then identify specific sequences by looking at the changes.
Rubins has a background in molecular biology. She conducted the test as researches simultaneously sequenced identical samples on Earth.
According to NASA, the test was set up in such a way as to make spaceflight situations – microgravity – the only variables that would account for any differences in results.
As this is a technology demonstration from commercially available hardware, researchers want to know if the device is durable enough to withstand launch conditions and operate with a degree of reliability in microgravity. One example would be the formation of air bubbles in the fluid that runs through the device.
"In space, if an air bubble is introduced, we don't know how it will behave," said Aaron Burton, a NASA planetary scientists and principle investigator, in a news release. "Our biggest concern is that it could block the nanopores."
Prior to launch, NASA tested the hardware in their underwater laboratory off the coast of Florida. The NASA Extreme Environment Mission Operation, or NEEMO, is located some 18 meters under the ocean. The tests went smoothly.
According to NASA, as researchers compare the ground results with the sequences collected in microgravity, so far everything seems to be matching up.
"A next step is to test the entire process in space, including sample preparation as well as performing the sequencing," said Sarah Castro-Wallace, project manager and NASA microbiologist.
If the testing goes well, it will make it possible for astronauts to know what is in their environment at any time.
"Onboard sequencing makes it possible for the crew to know what is in their environment at any time," Castro-Wallace said. "That allows us on the ground to take appropriate action – do we need to clean this up right away, or will taking antibiotics help or not? We can resupply the station with disinfectants and antibiotics now, but once crews move beyond the station’s low Earth orbit, we need to know when to save those precious resources and when to use them.”
Video courtesy of ScienceAtNASA
