Caption

White blood cell. Coloured transmission electron micrograph (TEM) of an eosinophil (white blood cell), part of the body's immune system. The cell's nucleus (green) contains chromatin (blue). In the cell's cytoplasm (also blue) are many enzyme-containing granules (green and black), used to destroy invading organisms. Eosinophils are found in many connective tissues and 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 (engulfing).