What is peripheral smear?

A peripheral blood smear is a thin layer of blood that is spread on a glass slide and stained to make the different types of blood cells visible under a microscope. The peripheral smear is used to evaluate the morphology of the red and white blood cells and platelets, and to identify any abnormalities in their number or appearance.

To make a peripheral blood smear, a drop of blood is placed on a glass slide and spread evenly into a thin layer using a spreader slide. The slide is then stained with Wright's stain, which differentially stains the different components of the blood cells. The Wright stain method colors the cells in the following way:

- Red blood cells: cytoplasm appears pink to orange, cell nucleus is not visible.

- White blood cells: cytoplasm varies from light blue to dark purple depending on the type of WBC, nucleus is clearly visible and stains dark purple.

- Platelets appear light to dark purple and resemble small dots or smudges.

Once the slide is stained, it can be viewed under a microscope to examine the morphology of the blood cells. The peripheral smear can provide information about the size, shape, and color of the blood cells, as well as any abnormalities in their number or appearance.

The peripheral blood smear is a commonly used diagnostic tool in hematology, and it can be helpful in diagnosing a variety of conditions, including anemia, leukemia, and thrombocytopenia.