And the most common type, the predominant antibody involved in allergic reactions, is immunoglobulin E. So immunoglobulin E is produced by the plasma cells. Now, what these immunoglobulin E antibodies do is they move on to the cell membrane of special wide blood cells found in the nearby tissue known as mast cells. So these mast cells contain these receptors that can bind to the constant region of our antibody, as shown in the diagram. Now, once the binding takes place, now, these antigens that were released by the pollen particles can move on and bind onto the variable portion on our antibody as shown in this diagram in section five. And once this binding takes place these mast cells in the cytoplasm contain these granules, these tiny vesicles that carry special chemicals, special immune chemicals such as histamine. And once the antigen binds onto the antibody found on the membrane of these mast cells, these mast cells release these vesicles, these granules and in turn release the histamine and other immune chemicals.