A peripheral blood smear or blood film is a type of blood test where a drop of blood is placed on a microscopic slide and then spread out with another slide over the length of the slide. It is then allowed to dry into a thin film. It is then dipped in methanol to fix the blood on the slide to preserve detail. It is then stained to differentiate different cells or parts of a cell. Once the smear has been prepared, it is examined underneath a microscope for abnormalities of blood cells or parasites.
Blood smears are used to diagnose or find evidence of anemia, sickle cell anemia, spherocytosis, eosinophils and malaria.