In the Proceedings of the National Academy of Sciences this week, Yale University scientists have developed a cheap, microfluidic platform that uses biocompatible ferrofluids "for the controlled manipulation and rapid separation of both microparticles and live cells." Using microspheres, they achieved 99 percent separation efficiency based on size at less than 10-micron resolution, demonstrating the platform's potential in "significantly reducing incubation times and increasing diagnostic sensitivity in cellular assays