Mice bred at the Jackson Laboratory By David GrimmFaced with her lab’s imminent closure, Sunny Shin had already begun to fear she would have to euthanize large numbers of the mice she works on.
Then, last Tuesday, the email came from her school’s vice provost of research. “In response to the public health crisis caused by COVID-19,” it read, “mouse/rodent users should cull their colonies as much as possible.”Shin, a microbial immunologist at the University of Pennsylvania Perelman School of Medicine, had to deliver the bad news to her lab manager: Euthanize 200 mice—more than three-quarters of their research animals—as quickly as possible.