White Blood Cell Differential Count Objectives To able

White Blood Cell Differential Count

Objectives To able to identify the different types of leucocytes under the microscope n To practice the procedure for differential leucocytes counting n To know normal values for the different white cell count n To know the importance of DLC in the diagnosis of disease processes. n

Definition The relative percentage of each type of white blood cells in peripheral blood. This experiment is a part of blood routine test.

Microscopic exam n 10× (low fold): overall smear quality, agglutination or parasites n 100× (oil Len): WBC Diff, RBC morphology

Observing direction: Observe one field and record the number of WBC according to the different type then turn to another field in the snake-liked direction *avoid repeat or miss some cells

Morphology of WBC in peripheral blood

normal peripheral blood smear

White blood cells n There are three types of granulocyte named according to their staining characteristics in blood films. They are neutrophils, eosinophils and basophils. n Agranular cells are divided into lymphocytes and monocytes.

Neutrophils n n n 62% of total WBCs Diameter: 10 -12 microns Cytoplasm: very pale blue Granules: staining (purple) Nucleus: dark purple blue 2 -5 lobes

. Neutrophils neutrophilic because they owe their colour to uptake of both the acidic and the basic components of the stain n

Eosinophil n Diameter: 13 -14 microns n Cytoplasm : full of orange- red coarse granules n Nucleus: n blue 2 lobes like a pair of glass n 2. 3%

Basophil n Diameter: 14 -15 n Cytoplasm: Granules: dark blue – black obscure nucleus n Nucleus: blue n 0. 4%

Lymphocyte n Diameter: small 7 -9 large 12 -16 n Cytoplasm : rim, clear, pale blue n Nucleus: purple red , oval indented 30% n

Normal lymphocytes n n Lymphocytes are the smallest WBC. They have large condensed nucleus, with a scanty pale blue cytoplasm.

Monocyte Diameter: 16 -18(are the largest normal blood cells) n Cytoplasm: The cytoplasm is abundant, sky blue in colour. n Some have vacuoles in the cytoplasm. n Nucleus: purple, large kidney shaped and slightly indented. n