Three scientists from the United States and Denmark were jointly awarded this year's Nobel Prize in chemistry for developing a way of “snapping molecules together” that can be used to design better medicines. Carolyn R. Bertozzi, Morten Meldal and K. Barry Sharpless were cited for their work on click chemistry and bioorthogonal reactions, which are used to make cancer drugs, map DNA and create materials that are tailored to a specific purpose.