SGD On Differential Leukocyte Count: Blood Smear Preparation, Staining & WBC Identification | MBBS

This is an essential medical lecture covering the Differential Leukocyte Count (DLC) practical for MBBS students (2025-2026 Batch). This session provides a step-by-step guide on performing one of the most fundamental skills in Hematology—preparing, staining, and analyzing a peripheral blood smear. Learn the proper technique for smear preparation, the crucial steps of Leishman staining, and the morphological criteria to accurately identify the five types of white blood cells (WBCs) under the microscope. This video is an invaluable resource for students preparing for their Physiology practical examinations. Lecture Breakdown & Timestamps Use these timestamps to quickly navigate to specific topics: I. Introduction to Hematology Practicals [00:00] Overview of Hematology practical competencies: DLC, Total Erythrocyte Count (TEC), Total Leukocyte Count (TLC), Hemoglobin Estimation, Bleeding Time (BT) & Clotting Time (CT), and Blood Grouping. [04:46] Starting the Procedure: Preparation and Staining of a Blood Smear. II. Blood Collection and Smear Preparation [05:15] Capillary Blood Collection: Proper technique for finger pricking (single, deep prick) and precautions to avoid mixing blood with tissue fluid. [08:35] Technique for making the Blood Smear: Using a second slide to draw a single-stroke smear and achieving the ideal "Tongue-Shaped Smear." [14:26] Staining the Smear with Leishman Stain: Detailed application process and counting drops for subsequent steps. III. Staining Chemistry & Cell Identification [16:16] Understanding the Staining Process: Fixation Time (2 minutes) Staining Time (10 minutes) after adding distilled/buffered water. Rule for adding distilled water (double the amount of stain). [21:23] Identifying Formed Elements of Blood (RBCs, WBCs, Platelets). [23:09] RBC (Erythrocyte) Identification: Pink structures without a nucleus; noting the difference in number and size compared to WBCs. [23:18] Leishman Stain Components: Eosin (stains cytoplasm/acidic parts, like RBCs and Eosinophil granules) and Methylene Blue (stains nucleus/basic parts). IV. Detailed WBC (Leukocyte) Morphology for DLC [29:58] Eosinophil: Bilobed, spectacle-shaped nucleus with large, coarse, pink-staining granules. [31:28] Neutrophil: Multi-lobed nucleus (2 to 7 lobes) with fine, faint granules. [32:38] Basophil: Rarely encountered in a routine count (0-1%)—recommended for beginners to avoid misidentification. [34:36] Lymphocyte: Rounded nucleus covering almost the entire cell, surrounded by a thin rim of cytoplasm (agranulocyte). [35:58] Monocyte: The largest WBC; characterized by a bean-shaped or kidney-shaped nucleus and abundant cytoplasm (agranulocyte). SANTINIKETAN MEDICAL COLLEGE & HOSPITAL Real Classroom Demonstration/Lecture On: PHYSIOLOGY by Dr. Akash Ghosh Roy (MBBS Batch: 2025-26) Conducted on: 18-11-25