blood disorders
Laboratory Tests for Blood Disorders
Blood smear
Although automated machines can rapidly determine the number of different blood cells and provide information about the size and shape of red blood cells and types of white blood cells, examining a blood sample under a microscope may provide additional information. To do this, a drop of blood is smeared across a glass slide to form a thin layer that makes it easy to see individual blood cells. The slide is then stained with colored chemicals to reveal specific characteristics of the blood cells and examined under the microscope. An experienced examiner can often obtain better information about cell counts, size and shape, and specific characteristics of the cells than a machine can. 