Researchers at Children’s Hospital Boston have built a microdevice to fight sepsis (blood infection), using magnetism to remove pathogens from blood.

They mixed blood with antibody-coated magnetic beads and sent the mix through microfluidic channels. A magnet pulled 80% of the bound pathogens (for this test the fungus Candida albicans) out in a single pass.

Most current treatments for sepsis are ineffective: each year it kills over 200,000 people in the U.S.