Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
A hand-spun centrifuge made of paper and string can separate plasma from whole blood in less than two minutes, and be used to diagnose malaria and other infectious diseases in areas without laboratory resources or electricity.