Using Chemistry to Talk to Bacteria Chemistry Professor Helen Blackwell studies the interface between chemistry and biology. She heads a lab of researchers who explore the way bacteria communicate among themselves, and is seeking to decode and co-opt these bacterial signals. Bacteria speak a chemical language that lets them signal to one another when it is time to swarm to form an infection or disease. Infectious bacteria use this process, called quorum sensing (QS), to form antibiotic-resistant communities known as biofilms. Beneficial bacteria use QS to initiate constructive relationships with their plant, animal, or human hosts. Professor Blackwell and her colleagues recognize that chemistry could be used to intercept and redirect these bacterial conversations. In her lab, they have started creating a chemical language to inhibit or stimulate QS. If successful, their work could someday help to impede infectious bacteria or encourage beneficial bacteria.