 Ever wake up after a good night's sleep and feel a slimy buildup on your teeth? That's called biofilm, and it's found almost everywhere bacteria are, from grimy kitchen corners to implantable medical devices and throughout our oceans. As bacteria multiply and colonize, they produce a cocktail of materials that form a protective barrier to its surroundings. As that barrier grows, bacteria within it find it easier to exchange signals and material, and sometimes they can even build resistance to certain antimicrobials. If scientists could record bacteria as they build these fortresses, they could develop ways of breaking into them and improve the treatment of infections. In keeping with the goals of the United Nations 2030 Agenda, an interdisciplinary team of researchers at Ames is dedicated to promoting good health and well-being, zero hunger, and clean water and sanitation by developing methods to accurately and quickly identify pathogens in biofilms and track biofilm formation. The key to their approach? A special class of chemical sensors called optotracers. Optotracers are small molecules that are chemically well-defined and light up when they dock with their targets. For bacteria producing biofilm, optotracers light up when binding on materials that make up the extracellular matrix. In a recent study, researchers used optotracers to lock onto a specific material bacteria used to form biofilms. Using salmonella as a model, the team found that bacteria deployed a protein appropriately named curly in a highly systematic way during biofilm construction. Upon contact with nutrients in a petri dish, the bacteria began to grow in an exponential rate, captured here in green. Once growth plateaued, the bacteria started to secrete curly and other biofilm ingredients, captured here in red. Biofilm formation closely followed bacteria growth, expanding radially and forming channel-like projections, fanning along the edge of each bacterial colony. This unique pattern suggests that cells within biofilms are specialized to execute certain functions, with some behaving like construction workers, to fortify colonies against their surrounding environment. The ability to watch this process unfold in real time using automated microscope technology could help scientists understand how biofilms form, how often, and what makes them so strong. Using salmonella as a model organism could provide insight into diseases such as urinary tract infections and even tuberculosis, where bacteria, although different, also produce biofilms using similar materials. Future studies will look at how biofilm formation and composition vary among different types of bacteria. Overall, Ames' effort into developing optotracing and other powerful point-of-care diagnostic technologies could enable faster and more precise treatments for patients.