Researchers around the world are using CRISPR systems for genome editing, with CRISPR-Cas9 as the best known example. However, there is still a great deal of uncertainty about how these types of systems work in the cell. Researchers at Delft University of Technology and Wageningen University & Research have now followed one such system, the so-called CRISPR Cascade complex, during the hunt for hostile DNA for the first time. The bacterial defence mechanism is astonishingly fast and efficient: it checks no less than 100 different pieces of DNA every second. Read more