False color scanning electron micrograph (SEM) of sickle cells from a patient with sickle cell disease (drepanocytosis), a form of anemia. It is a hereditary blood disease characterized by an abnormal type of hemoglobin, called sickle-cell hemoglobin, in the red blood cells. This type of hemoglobin, when deprived of oxygen, precipitates out, forming elongated crystals that distort the shape of the red blood cell. Sickle cells are rapidly removed from the blood, causing anemia. There is no satisfactory cure for the disease. Magnification: x5550 at 35 mm size.