When Dr. Robert Brown started teaching physics at Case Western Reserve University, he had no idea he’d be using his expertise in magnetic fields to hunt malaria. The earlier malaria is diagnosed, the more likely you are to survive, but most lab techniques can’t be used in rural villages.
“We wanted to diagnose malaria with something fast, portable, and cheap and accurate, which sounds challenging, but in fact we were able to really do it,” Brown said.
Brown, his physics team, and his colleague from Case Western’s Center for Global Health and Diseases, Dr. Brian Grimberg, worked up an idea. The key is that when the malaria parasite invades red blood cells, it can’t digest the iron in the cells.
“So it sequesters it - it tries to separate it out. And when it does that, it actually ends up making this little magnetic crystal, this iron crystal. So those little crystals are floating around in the infected blood,” Brown said.
If you hold a refrigerator magnet near a sample of this infected blood, you can line these iron crystals up in the magnetic field. Then, if you shine polarized light from a laser through it, the lined-up crystals will block the light, just like your polarized sunglasses.
“Even when you have just a one part in a million of infected blood molecules, you end up being able to see the difference,” Brown said.