Mouse splenocytes are stained with Anti-Mouse CD19 Monoclonal Antibody(AF488 Conjugated)[Used at 0.2 μg/106 cells dilution](filled gray histogram). Unstained splenocytes (blank black histogram) are used as control.
CD19 is a 95 kD glycoprotein also known as B4. It is a member of the Ig superfamily, expressed on all pro-B to mature B cells (during development) and follicular dendritic cells. Plasma cells do not express CD19. CD19, in association with CD21 and CD81, forms a molecular complex integral to B cell activation.