Sickle cell anaemia. Coloured light micrograph of a blood smear showing distorted red blood cells in sickle cell anaemia (drepanocytosis). Sickle cell anaemia is an inherited blood disease, so-called because red blood cells have abnormal haemoglobin (oxygen-carrying pigment) that distorts cells into a sickle shape. Here, normal red blood cells (rounded) contrast with sickle-shaped cells (at centre). Sickle cells are fragile and easily destroyed in the bloodstream. Sickle cell anaemia occurs largely in African people, and can be fatal in childhood. No cure is yet known. Magnification: x800 at 6x4.5cm size.