False- colour scanning electron micrograph of a deformed red blood cell in sickle cell anaemia (drepanocytosis), a hereditary blood disease that affects negroes. Sickle cell disease is characterized by the production of abnormal haemoglobin (Hbs) in red blood cells. Hbs becomes insoluble when the blood is deprived of oxygen and precipitates, forming elongated crystals that distort the blood cell into the sickle shape. These deformed red cells are rapidly removed from the circulation, leading to anaemia. There is no satisfactory treatment. Magnification: x1655 at 35mm size. Coloured pink.