Neutrophil white blood cells. Coloured transmission electron micrograph (TEM) of neutrophils (pink), a type of white blood cell (leukocyte). These cells are phagocytic, that is they engulf and digest materials from their surroundings. They contain enzymes that are used to digest invading bacteria and are highly mobile, migrating quickly to areas of tissue damage from local blood vessels. This is a cause of inflammation. These particular neutrophils are from a patient with ulcerative colitis, an inflammatory disease of the rectum and colon. They are in the majority, which suggests an acute attack. Magnification: x1400 when printed 10 centimetres wide.