Lymph Node Secondary Follicle

This is a medium power view of a secondary follicle in a lymph node. Note the pale germinal center, which contains proliferating B-cells and follicular dendritic cells. As B-cells proliferate, they undergo somatic hypermutation (mutation of the immunoglobulin gene) in order to enhance the binding affinity between the antigens and the antibodies. The mantle zone of the follicles contains resting and memory B-cells.