Question

Discuss justifications for performing a manual morphology review and the steps in the performance of a peripheral blood smear examination.

Answer 1

Peripheral blood smears are usually carried out to identify the abnormal cell components of huma blood and to learn about its morphology. Any variation from the normal morphology of blood cells may indicate abnormality of the cell with its function. The peripheral blood smear will helps to identify the abnormal morphology of cells, the number of cells etc. Various hematological disorders are associated with abnormal morphology of the blood vessels.RBC are the concave shaped blood cells in normal way, but in tallassemia, sickle cell anemia and iron deficiency anemia situations, the shape of the RBC will vary.the same way there is alterations in the WBC morphology also. In many of the severe parasitic infections, the WBC morphology will change.hence morphology review of blood cells will helps to identify the underlying cause and types of disease conditions. In many hematological conditions like jaundice, low hemoglobin, anaemia, leucocytopenia, thrombocytopenia etc there will be variation in the number of cells and morphology of cells.

Some of the common morphological variations are oval shaped RBC called ovalocytes,seen in thalassemia. Spherical shaped RBC called as spherocytes seen in heriditary spherocytosis.Elliptocytes, where the RBC will be in elliptical shape found in megaloblastic anemia.Tear drop shaped RBC seen in some form of megaloblastic anemia, sickle shaped RBC in sickle cell anemia etc.

The Peripheral blood smears are usually performed in the laboratory. Correct techniques to be followed for avoiding errors and to obtaine accurate results. The blood sample can be collected from lancet prick on the fingers following antiseptic rub or can take one drop of venous blood. Blood sample from EDTA sample are also advisable. The blood sample is placed in a sterile glass slide. With the edges of an another glass slide at a 30 degree angle,the blood drop is spreaded in the first slide. use only single strokes to spread the blood in to the glass slide and make a thin film of blood. Later allow the smear to air-dry. Label the blood smear with patient’s name, date and IP or OP number.

The air-dried smear is stained later for microscopic examination.The smear is flooded with stain fo 3 minutes. After staining technique, diluted with distilled water and allow to stand for 10 minutes.The slide is thoroughly rinsed under running water and the back side and sides of the slide is wiped well to remove the excess stain.The slide is then made to dry. Later the smear is examined under the powerful microscopes to identify the abnormal morphology, abnormal cell count etc. For that different magnification of the microscope is used. Abnormal cells, altered morphology, presence of any parasites, any fibrin clots etc are monitored by a trained laboratory person.