What steps are involved in preparing a peripheral blood smear and performing a basic cell morphology assessment?

• A. Make a thick smear and examine at low power only.
• B. Stain with Gram stain and examine; record Gram-positive and Gram-negative counts only.
• C. Fix the smear, stain with Wright-Giemsa, and examine under oil immersion for RBC morphology, WBC differential, and platelet estimation; note artifacts.
• D. Prepare multiple smears and count only WBCs.

Answer: (C)

To assess peripheral blood cell morphology, you start with a well-made thin smear, allow it to air-dry, fix the cells with methanol, and stain with Wright-Giemsa. This combination highlights the features of red cells, white cells, and platelets so you can evaluate them clearly under high magnification, typically using oil immersion. By examining RBCs, you look for shapes and sizes (anisocytosis, poikilocytosis), inclusions, and abnormal forms. The WBCs are identified and counted to generate a differential, distinguishing neutrophils, lymphocytes, monocytes, eosinophils, and basophils, and you estimate platelets to gauge thrombopoiesis. It’s also important to note any artifacts—such as staining problems, air-drying artifacts, or smearing issues—that could mislead interpretation.

This approach is the standard because Wright-Giemsa staining provides good contrast between cytoplasm and nucleus across all cell types, and oil immersion is needed to resolve the fine details of morphology and accurately size and count cells. The other options miss essential steps or goals: Gram staining isn’t used for blood cell morphology, thick smears or low-power viewing don’t reveal the necessary cellular details, and counting only white cells neglects RBC and platelet information.