Blymphocyte. Coloured Scanning Electron Microgr aph of a group of Blymphocyte white blood cells. The cell surfaces are covered with tiny ridges and projections called microvilli, which help it bind to target proteins. Bcells account for 10% of the bodys lymphocytes. On encountering a foreign antigen, such as a bacterial surface protein, the immature Bcell either divides into a number of plasma cells, which produce antibodies that kill the invader, or it matures into a memory cell. Memory cells remain in the body for years, giving immunity to the original pathogen. Magnification x2000 at 6x7cm size.