Germinal centers is place were B cells proliferates and undergoes both isotype switching and somatic hyper mutation,B cells are formed within Bcell follicle and lymphoid organs.
Formation of germinal center starts when dendritic cells display antigen on the surface ,which activates Antigen specific CD4 Tcells,which proliferate and mature into affector cells capable of activating Antigen specific B cells.
B cells enter into the follicle and begins to proliferate rapidly ,During this time it also undergoes somatic mutation to introduce new variation in the B cell receptor.
B cell undergoes process of selection after somatic mutation .When the receptors are tested for the ability to bind the antigen.
Those who fail to bind or fail to compete efficiently with other B cell receptors will die.