All cells in the brain are covered in carbohydrates, such as heparan sulfate (HS), which plays a critical role in forming neuronal connections as well as in neurodegenerative conditions like Alzheimer’s disease. However, it has long been challenging to study this important carbohydrate without removing it from its biological context. As a BroadIgnite awardee, Shiwei will tackle this by building a set of novel optical sequencing tools that can visualize and profile individual HS molecules in intact biological samples—work that can advance our understanding of HS and its neurobiological functions.