A diagnostic test involves placing a small drop of blood onto a glass slide, which is then examined under a microscope. The blood film is stained with dyes to enhance the visibility of blood cells, enabling clearer observation and analysis.
This test enables the assessment of the shape and appearance of blood cells to identify any abnormalities, such as the distinctive sickle-shaped red blood cells associated with sickle cell anemia. Additionally, it allows for the quantification of different types of white blood cells, known as a differential white cell count. This examination can be valuable in diagnosing infections or leukemia. Blood films are also utilized in the diagnosis of infections where parasites are visible within red blood cells, with malaria being a notable example.
Blood film tests are typically conducted in conjunction with a full blood count.