The first time we tested our MediSieve antimalarial device in human samples was a nerve-wracking experience. As I sat in the Malaria Group’s lab at Colombia’s University of Antioquia, I had my doubts. I was confident that the theory was sound; like a dialysis machine, MediSieve would filter the blood of malaria patients, making use of the natural magnetic properties of infected cells to capture them in a magnetic filter. But would it work in practice? I’d done a whole lot of modeling back in London, and even some preliminary tests in mouse models – and those results had been positive enough to convince The Rosetrees Trust to fund my research trip. But as I watched my collaborators peer down their microscopes at the blood samples, I had the uncomfortable realization that if the answer wasn’t what we hoped for, the project was in serious trouble.

While I was busy imagining various worst-case scenarios, the scientists finished their cell counts. They turned to me and smiled. “It worked.”

Want to go from scientist to CEO?