How CRISPR works

Back in 2011, Jennifer Doudna, a biochemist and molecular biologist at the University of California, Berkeley, and Emmanuelle Charpentier, now at the Max Planck Institute for Infection Biology in Germany, grew intrigued by the way bacteria use a molecular system known as CRISPR-Cas9 to respond to viral attacks. For years, bacteria were assumed to be primitive creatures with rudimentary immune…