NASA isn’t saying it’s aliens — but the space agency is touting its ability to identify organisms using the first DNA sequencer in orbit.
Oxford Nanopore Technologies’ palm-sized MiniON sequencer was sent up to the International Space Station last year, and it’s now been paired up with a DNA replicator that’s able to amplify genetic samples through a process known as polymerase chain reaction, or PCR.
Together, the devices were employed to check bacterial samples as part of an experimental campaign called Genes in Space-3.
NASA astronaut Peggy Whitson, who has a Ph.D. in biochemistry, collected the bacteria for the experiment by touching petri plates to various surfaces of the space station. After culturing the bacterial colonies for about a week, she transferred samples to miniature test tubes inside the station’s Microgravity Science Glovebox.
As Whitson was putting the samples through PCR amplification in August, a hurricane was taking aim at Texas.
“We started hearing the reports of Hurricane Harvey the week in between Peggy performing the first part of collecting the sample and gearing up for the actual sequencing,” NASA microbiologist Sarah Wallace, the principal investigator for Genes in Space-3, said in a news release.
Because of the storm, Wallace couldn’t get to NASA’s Johnson Space Center to talk Whitson through the experiment. Instead, NASA had her place a cellphone call to Marshall Space Flight Center in Alabama, where the Payload Operations Integration Center patched her through to the space station.
With Wallace’s guidance, Whitson put the DNA through the sequencer, and the readings were downlinked to Houston.
“Once we actually got the data on the ground, we were able to turn it around and start analyzing it,” said NASA biochemist Aaron Burton, a co-investigator for the project. “You get all these squiggle plots, and you have to turn that into A’s, G’s, C’s and T’s.” Those chemicals — adenine, guanine, cytosine and thymine — are the four “letters” in the genetic alphabet for the code of life.
NASA’s scientists had previously used the sequencer to check the genetic signatures of prepared samples, when they knew what they were looking at. This was the first time unidentified samples were sequenced for identification.
“Right away, we saw one microorganism pop up, and then a second one, and they were things that we find all the time on the space station,” Wallace said.
When the samples were brought back to Earth with Whitson aboard a Soyuz spacecraft in September, Wallace and her team ran additional rounds of DNA tests to verify that the identifications were correct.
They were.
“We did it,” microbiologist Sarah Stahl said. “Everything worked perfectly.”
Even though the bacteria were not of alien origin this time around, the sample-to-sequence method tested in the experiment could be used to identify exotic microbes on Mars or other extraterrestrial locales. A more down-to-earth application would be to assist with the diagnosis and treatment of astronauts’ ailments during long-duration missions.
“As a microbiologist, my goal is really so that when we go and we move beyond ISS, and we’re headed toward Mars or the moon, or wherever we’re headed to, we have a process that the crew can have that great understanding of the environment, based on molecular technology,” Wallace said.
The Genes in Space-3 experiment was developed for the ISS National Lab by NASA’s Johnson Space Center and Boeing, and managed by the Center for the Advancement of Science in Space.
