What are the types of blood smear?
- A thick blood smear is a drop of blood on a glass slide. Thick blood smears are most useful for detecting the presence of parasites, because they examine a larger sample of blood.
- A thin blood smear is a drop of blood that is spread across a large area of the slide.
What microscope is used for blood smears?
scanning electron microscope
Peripheral blood smears prepared routinely from nonneoplastic and leukemia cases were studied using the scanning electron microscope (SEM). The peripheral blood glass slide is examined directly in the SEM following application of a thin carbon coat.
What magnification does a blood smear need?
When examining a peripheral blood smear, a hematologist starts with a low magnification objective, typically a 20x or 10x. The hematologist gets an overview of red and white blood cell densities, the amount of erythrocytes, its color and rough morphology and if obvious cellular inclusions are present.
Which method is used for blood smear staining?
Blood films are routinely stained with a Romanowsky-type stain (e.g., Wright or Wright-Giemsa) either manually or using an automatic slide stainer. Romanowsky-type stains are composed of a mixture of eosin and oxidized methylene blue (azure) dyes.
What is malaria smear?
Malaria parasites can be identified by examining under the microscope a drop of the patient’s blood, spread out as a “blood smear” on a microscope slide. Prior to examination, the specimen is stained (most often with the Giemsa stain) to give the parasites a distinctive appearance.
What is the difference between thin and thick smear?
A thick blood smear is a drop of blood on a glass slide. A thin blood smear is a drop of blood that is spread across a large area of the slide.
How does Wright’s stain work?
Wright’s stain is a polychromatic stain consisting of a mixture of eosin and methylene Blue. When applied to blood cells, the dyes produce multiple colors based on the ionic charge of the stain and the various components of the cell.
What type of slide would you use for a blood smear?
Use clean, high-quality microscope slides. Aim for a blood droplet size of 4mm diameter. Optimise spreading speed for length and a good feathered edge. Hold the spreader slide at 30-40 degrees to achieve optimal smear length.
What is the feathered edge of a blood smear?
The smear itself should look very smooth with a seamless progression to what is called a “feathered edge”. This is the very end area of the smear and consists of a monolayer of cells. The monolayer will contain cells that are the easiest to identify and are the least distorted.
What happens to a blood smear if it is too thick?
Insufficiently dried smears (and/or smears that are too thick) can detach from the slides during staining. The risk is increased in smears made with anticoagulated blood. At room temperature, drying can take several hours; 30 minutes is the minimum; in the latter case, handle the smear very delicately during staining.
What is coverslip technique?
To create a coverslip smear preparation, a coverslip is picked up by the corner and the point is held between the thumb and forefinger in one hand. The other hand uses a capillary pipette to transfer a small drop of concentrated bone marrow on to the center of the coverslip.
What are the three methods of preparing a blood smear?
Four different types of smear preparation methods (conventional method, blood film method, drop and rest method, and water-wash method) were carried out according to the standard reference as described below.
What are neutrophils in a blood smear?
Neutrophils are the commonest type of white blood cell found in a blood smear. They make up 60-70% of the total amount of white blood cells. Neutrophils have 3 types of granules: azure granules (lysosomes),
How big are lymphocytes in a blood smear?
This is a photo of a lymphocyte in a blood smear. Most of the lymphocytes are small; a bit bigger than red blood cells, at about 6-9µm in diameter, The rest (around 10%) are larger, about 10-14µm in diameter.
What are eosinophils in blood smears?
Eosinophils are fairly rarely found in blood smears – making up 1-6% of the total white blood cells. Function : These cells are born in the bone marrow, and migrate from the peripheral blood system after a few hours, into loose connective tissue in the respiratory and gastointestinal tracts.