ct_002. Human Blood smear (adult)
(Romanowski-Giemsa stain)
1. Look at the blood cells on the slide. Make sure, most of them are circular-shaped, oxyphil-colored and placed randomly.
2. Learn to differentiate the blood elements:
- erythrocyte - a disk-shaped nucleus free cell (postcellular structure) with diameter 7,2-7,5 micrometers; due to the discoid shape the thinner central part gets stained with eosin less intensively;
- neutrophilic granulocytes (neutrophils) - are blood cells 10-15 micrometers in diameter characterized by minor purple-colored grains in the cytoplasm (types: band cell - a cell with a non-segmented nucleus, looking like curved stick or a horse-shoe-shaped; segmented neutrophil - a cell with an intensively colored nucleus containing 2-5 segments which are connected by fine threadlike structures);
- eosinophilic granulocyte (eosinophil) - is a circular cell 12-15 micrometers in diameter with a nucleus usually containing 2 lobes; the cytoplasm is filled with numerous eosinophilic granules;
- basophilic granulocyte (basophil) - is a circular cell with diameter 12-15 micrometers having a lobulated nucleus (2-3 segments)or an S-shaped nucleus; the cytoplasm contains stained large basophilic granules (0,5-2 micrometers);
- a lymphocyte - is a circular cell having a round, oval or bean-shaped dark nucleus which takes up to 90% of the cell; it has a narrow rim of basophilic cytoplasm (the diameter of small lymphocytes is 6 –7 micrometers, medium – 8-10 micrometers);
- a monocyte - is the largest leukocyte with diameter 18-20 micrometers; the nucleus is light-colored and has an eccentric location; the nucleus is bean- or horse-shoe-shaped (takes up to 50% of the cell’s area on the slides); the cytoplasm is poorly basophilic;
- blood platelets - is an aggregation of small nucleus free post-cellular structures with diameter 2-4 micrometers; are composed of the pale transparent outer part (hyalomere) and the central part which is colored (granulomere).
3. Draw and point out all types of blood corpuscles.
See to adequate correlation of sizes when drawing different types of cells (on the slides blood corpuscles are spread on the glass slide and usually look larger than life-size in the blood stream or in the histological sections.