Food allergies are an emerging challenge in public health in the industrialized world, affecting 5% of children in the United States (NIH). Accidental exposure can be life threatening, and currently the only reliable strategy for preventing these reactions is avoidance. Allergic reactions are mediated in part by certain immune cells (T cells and B cells) that inappropriately respond to food antigens. Because the antigen-specific cells that mediate these allergic reactions are extremely rare, the inability to identify and isolate them has been a long-standing limitation to studying allergic responses. We are working to overcome this limitation using nanowell technologies to identify antigen-specific cells, enabling us to study allergic reactions at a greater resolution than has previously been possible. We seek to apply insights gained from this approach to better understand the pathogenesis of food allergies, and to design and improve therapies for allergic individuals.