Peripheral blood Practical lesson WS 10 – group 1051

Teacher: Tomáš Kučera

Preparation, staining and evaluation of the blood smear

Blood cells are studied in smears prepared by spreading of a drop of peripheral blood in a thin layer on the microscopic slide.

Procedure:

Disinfection

of the skin of the fingertip of the left fourth or third finger (at right-handers)

Puncture

into the ball of fingertip with sterile lancet or single-use needle

The first drop

of blood is wiped off because blood is diluted by tissue fluid

The second drop

of blood is placed near an end of a glass (microscopic) slide and spread using another slide (called “spreader” slide)

Spreading

: spreader slide is moved over the glass slide at an angle of 45 º, when slide edge touches the blood drop, the blood spreads by capillary forces along its edge. A thin film of blood is obtained by a smooth quick motion of the spreader slide across a glass slide. The air dried blood smear is fixed and stained.

Blood smears are stained with mixtures of acidic (eosin) and basic dyes (methylene blue and its oxidation products – methylene violet and azure)

PAPPENHEIM ´S METHOD

Method is used for staining of peripheral blood and bone marrow smears

Fixation

of blood smear with May Grünwald solution (eosinate of methylene blue in methanol) .......... 3 min.

Staining

with diluted May Grünwald solution (the same amount of distilled water was added) ......... 1 – 2 min.

Pour off mixture

Staining

with Giemsa-Romanowsky (eosinate of the methylene azure, blue and v iolet) …………….. 15 min.

Washing

(distilled water), air-drying

Results of staining:

red blood cells – pink/red, nuclei – purple/blue, neutrophilic granules – salmon pink, eosinophilic granules – brick-red, basophilic granules – blue/violet, cytoplasm of lymphocyte – sky blue, cytoplasm of monocyte – pale blue (grayish or greenish), azurophilic granules - purple red

Evaluation of the blood smear

Blood smear is observed in light microscope using HI objective (oil.im.,100x) and immersion oil

RBC evaluation : size, shape, structure anisocytosis (microcytosis, macrocytosis), poikilocytosis - variation in RBC shape: spherocytosis, ovalocytosis, sickle cells WBC evaluation : size and morphology Leukogram (differential leukocyte count) -

proportional incidence

(%) Arneth formula -

reflects ratio of the neutrophilic granulocytes based on the number of nuclear lobes. Shift to left - predominance of the young forms (band and two lobes). Shift to right - predominance of the old forms (four and five lobes).

FORMED ELEMENTS

blood cell count (number per μL or L) ERYTHROCYTES - Male: 4.5-6.0 x 10 12 / L Female: 4.0-5.2 x 10 12 / L LEUKOCYTES – 4.000 - 10.000 per μL (4 – 10 x 10 9 / L) LEUKOGRAM (differential leukocyte count) Neutrophils: 60-70 % (band form: 2-5 %) Eosinophils: 2-5 % Basophils: 0-1 % Lymphocytes: 20-40 % Monocytes: 2-10 % THROMBOCYTES - 150.000 - 400.000

per μL

Ly NG

band form NG

Ly Eos

Mo

NG BG Mo