Peripheral Blood Smear Lab Report

A peripheral blood film is a laboratory work-up that involves the cytology of peripheral blood cells smeared on a slide. It focuses on three main blood cells: red blood cells, white blood cells and platelets. A peripheral blood smear is invaluable in the characterization of various clinical diseases. Initiation of a PBF is often a clinical request based on clinical suspicion. It may be initiated based on abnormal findings from an automated count or patients clinical information whose diagnosis maybe supported by a peripheral blood film.

The viscosity of the blood is an important factor when making a blood smear. There are three basic techniques that are employed in the preparation of a peripheral blood smear. Firstly, the cover slide method,

Wright’s stain and Wright-Giemsa stain are used as methanol solutions. The blood cells are fixed by the methanol in the first step of the staining reaction, when the Wright’s stain and Wright’s-Giemsa dye mixture is added to the blood film. Both Wright’s stain and Wright- Giemsa stain are adaptation of polychrome Romanowsky stains. Such polychrome stains produce multiple colors when applied to cells because these stains are composed of both basic and acidic aniline dyes. Romanowsky stains contain methylene blue (a basic dye), eosin (an acidic dye) and methylene azure (an oxidation product of methylene blue also referred to as polychrome methylene blue). Variations of the Romanowsky stain differ in the way the methylene azure is produced to the stains. Polychrome stains produce multiple colors because they dye both acid-base reactions. The acidic cell component, such as nuclei (nuclear DNA) and cytoplasmic RNA, are stained blue-violet by basic methylene azure. They are called basophilic because they stain with the basic dye. The more basic cell components, such as hemoglobin and eosinophilic granules, are stained orange to pink and are called acidophilic because they stain with acidic dye. Some structures within the cells stain with both components, such as neutrophilic granules, whereas the azurophilic granules stain with methylene azure. (Patel