Peripheral Blood Smear Quiz Questions And Answers

Wright's stain and Giemsa stain are both commonly used hematology blood stains. Wright's stain is a combination of eosin and methylene blue, which allows for the differentiation of various blood cells. It stains the cytoplasm of cells pink or orange, and the nuclei blue or purple. Giemsa stain, on the other hand, is a mixture of eosin and methylene blue with additional components. It is used to stain blood smears for the identification of blood cells and parasites. Both stains are important tools in hematology for the examination and analysis of blood samples.

A properly stained smear should appear pinkish-blue to the naked eye because staining is a technique used in microscopy to enhance the visibility of cells or structures. Different stains can be used to highlight specific components of the sample. In this case, the pinkish-blue color indicates that the stain used successfully highlighted the desired structures or cells in the smear, allowing for better observation and analysis.

Methanol is commonly used as a fixative in microbiology to preserve bacterial smears. It denatures proteins, stops metabolic processes, and prevents autolysis, thereby preserving the cellular structure. Ethanol can also be used as a fixative, but methanol is preferred due to its better penetration and ability to preserve delicate structures. Eosin and methylene blue are stains used for staining rather than preserving smears.

All smears should be stained within 1 hour of being prepared because smears are delicate and can deteriorate over time. Staining the smears within 1 hour ensures that the cells are preserved and the staining process accurately reflects the characteristics of the cells. If the smears are stained after 1 hour, the cells may degrade or become distorted, leading to inaccurate results. Therefore, it is crucial to stain the smears promptly to obtain reliable and valid information from the staining procedure.

Capillary blood is the most preferred specimen for blood smear because it is easily accessible, requires minimal patient discomfort, and provides a representative sample of the patient's blood. Capillary blood is obtained by pricking the fingertip or earlobe, and it contains a mixture of arterial and venous blood. This specimen is commonly used for point-of-care testing, such as glucose monitoring, and it is suitable for microscopic examination to assess blood cell morphology and other parameters. Additionally, capillary blood smears are often used in pediatric patients or individuals with difficult venous access.

The given procedure describes a two-step method for the Wright's stain procedure. In this method, the smear is placed on a staining rack and flooded with Wright's stain. Then, an equal volume of buffer is added dropwise. This two-step process ensures proper staining of the smear and helps in achieving accurate and reliable results. Therefore, the correct answer is the two-step method.

The correct answer is A moving belt that carries slides through the staining reagent. This answer accurately describes one of the two types of automatic stainers, which involves a moving belt that carries slides through the staining reagent. This method allows for a continuous and automated staining process, ensuring consistent and efficient staining of slides.

Smears from anticoagulated EDTA blood should be made within 2 hours of blood collection. This is because EDTA is an anticoagulant that prevents blood from clotting, but it can also cause changes in the blood cells over time. Making the smears within 2 hours ensures that the blood cells are still in their original state and provides accurate results for microscopic examination. Waiting longer than 2 hours may lead to distortion or degradation of the blood cells, compromising the quality of the smear.

Blood smears need to be stored in a dust-free environment to prevent any contaminants from affecting the samples. Storing them in a dark place is necessary to protect the samples from light exposure, which can cause degradation. Additionally, keeping the smears protected away from moisture is crucial to prevent any potential damage or alteration to the samples. Storing them in a wet box is not recommended as it can introduce excess moisture, which can negatively impact the integrity of the blood smears.

A good blood smear should cover a significant portion of the slide, about three-fourths, to ensure an adequate sample for examination. The smear should also demonstrate a gradual transition from thick to thin, indicating proper spreading of the blood cells. A smooth appearance without any holes or ridges is important to prevent artifacts that may interfere with accurate analysis. A feathered edge of about 1.5 cm in length helps to create a thin and even distribution of cells. Microscopically, the cells should be evenly distributed, allowing for a thorough examination of their morphology. Additionally, there should be an area at the thin end of the smear where red blood cells are not overlapping, ensuring clear visibility. The smear should appear black, indicating proper staining and contrast.

The end of the spreader slide is brought to rest at a 10-15 degree angle in front of the drop of blood when using a two slide (wedge) method of preparing a peripheral blood smear. This angle allows for an optimal spread of the blood sample on the slide, ensuring that the cells are evenly distributed and well visualized under the microscope. A steeper angle may cause the blood to spread too thin, while a shallower angle may result in clumping of the cells.