Emory University Hospital will begin stockpiling blood plasma from Ebola survivors, treated with a pathogen inactivation system that’s never been used before in the United States, the company that developed the technology announced on Friday. So far, the US has had some amazing success in curing Ebola, possibly thanks to experimental plasma treatments. Drawn from survivors, the stuff comes enriched in antibodies that could help to fight off the disease—but it also has the potential to carry other diseases, like malaria, that are common in west Africa where Ebola is raging. The new system will kill off any extra contaminants that may be lurking in this potentially live-saving serum. It’s the same one, Cerus Corporation’s Intercept system, that will be used in a Gates Foundation-funded study of Ebola treatments in West Africa. The pathogen-killing molecule at the heart of the system is amotosalen, part of a class of three-ringed molecules called psoralens. They’re the compounds in lime that cause what some doctors call “Mexican beer dermatitis”: Get a squirt of the citrus on your skin when you push it into your Corona, spend a few hours on the beach in the sunlight, and the molecules interact with the UV rays to give you a nasty rash. Amotosalen doesn’t cause dermatitis, but it works by the same mechanism. When technicians add it to blood plasma, it nestles in the middle of DNA and RNA helices, linking the bases on either side. Then, activated by a burst of UV light, it irreversibly bonds to those bases—so the genetic material can’t replicate any more. Pathogens, inactivated. Europe has long used blood purification systems—Intercept was first approved eight years ago, and there are other techniques, too. But the FDA has been slow to approve the same technology in the US, mostly, it seems, for lack of demand. Last week the agency approved the technique for restricted use in treating the plasma of Ebola survivors. More via WIRED.