TBL12 - Blood Smears Flashcards
How are blood cells screened microscopically? How can one distinguish red blood cells on a blood smear?
1) Blood cells (aka formed elements of blood because RBCs and platelets are anucleate) are screened microscopically by evenly spreading a drop of blood across a glass slide to create a thin film or blood smear
2) Staining the smears with eosin (orange-red to pink dye), basic dyes (dark blue dye) and neutral dyes (faint pink dye) enables distinction of the blood cells
What color does the cytoplasm of RBCs typically stain? What color do the nuclei of leukocytes typically stain?
The cytoplasm of RBCs typically stains orange-red to pink and the nuclei of leukocytes (aka white blood cells) stain dark blue
What determines the names of cytoplasmic granules in leukocytes?
Different staining affinities of the cytoplasmic granules in leukocytes determine their names i.e., large granules of eosinophils and basophils are stained orange-red to pink by eosin and deep blue by the basic dyes
What are the fine granules of neutrophils stained? What are monocytes and lymphocytes stained?
1) The fine granules of neutrophils are stained faint pink by neutral dyes
2) Monocytes and lymphocytes lack granules but lysosomes in their cytoplasm are stained light reddish blue by the combination of dyes
What is the ratio of erythrocytes to leukocytes in blood smears? What are lymphocytes comparable in size to? What is the relative size of other leukocytes?
1) Normal blood smears are present 600:1 in erythrocyte/leukocyte ratios
2) Lymphocytes are typically comparable in size to RBCs and the other leukocytes are larger than RBCs in normal blood smears
What are the relative frequencies of leukocytes in normal blood smears in decreasing order?
Relative frequencies of leukocytes in normal blood smears are in decreasing order: neutrophils, lymphocytes, monocytes, eosinophils, and basophils
