Just as the pandemic hit, Christina Islas Lynggaard—a postdoc researcher at the University of Copenhagen’s Globe Institute—sat in her apartment surrounded by vacuums and filters. She tested them, eventually landing on a water vacuum, which was, for her purposes, pretty good. The rest didn’t quite make the cut—they had good suction, but the second you put a filter in them, it messed with their power supplies. “It just dies, and then the motor comes to overheat, and it was very difficult,” Lynggaard said.

All this testing was done for an interesting case, one that seems obvious in hindsight but could have valuable ecological applications. In short, Lynggaard and other researchers on her team were looking for a way to collect environmental DNA (eDNA) from the air to measure biodiversity or look for the presence of rare or invasive species.

Out of thin air

“We had no idea the best way to collect DNA from air,” Kristine Bohmann told Ars. Bohmann is an associate professor at the Globe Institute and one of the researchers involved in the effort.