Not to mention that even if they were able to, the sheer amount of contaminants in that OR would have fucked the samples. Black mold's growing on the walls, Jerry's wearing dirty hiking boots, they claim Ellie's prepped for surgery yet they didn't shave her head (the first fucking thing you do when you prep someone for brain surgery).... the Fireflies were so absurdly incompetent that it's a miracle they hung on for as long as they did. It's funny how Neil tries to posit them as the good guys when only things they ever did was butcher immune people in grody ORs and destroy a bunch of QZs that were keeping thousands safe from the fungus. So much for trying to restore the world.