Comparison between a scanning election micrograph (SEM top) and transmission electron micrograph (TEM bottom) of an eosinophil (white blood cell). Eosinophils are part of the body's immune system. In the TEM image the cell's nucleus (green) contains chromatin. In the cell's cytoplasm (blue) are many enzyme-containing granules (red), used to destroy invading organisms. Eosinophils are involved in the body's allergic response and also help to defend the body from invading parasites. They are capable of ingesting and destroying foreign particles by a process known as phagocytosis. Magnification: x5000 when printed 10 centimetres wide. For a series of comparisons between SEMs and TEMs see images C047/7006 to C047/7034.