Thick smears consist of a thick layer of dehemoglobinized (lysed) red blood cells (RBCs). The blood elements (including parasites, if any) are more concentrated (app. 30×) than in an equal area of a thin smear. Thus, thick smears allow a more efficient detection of parasites (increased sensitivity).
Likewise, people ask, how do you prepare a thick and thin blood smear?
Making thick and thin blood smears Thin film (a): Bring a clean spreader slide, held at a 45° angle, toward the drop of blood on the specimen slide. 3. Thin film (b): Wait until the blood spreads along the entire width of the spreader slide.
Similarly, why is a thick blood smear considered to have a higher sensitivity than a thin blood smear? Thick blood smears are more sensitive in detecting malaria parasites because the blood is more concentrated allowing for a greater volume of blood to be examined; however, thick smears are more difficult to read. Thin smears aid in parasite species identification and quantification.
Consequently, what is thick and thin 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.
Why thick smear is not fixed?
Insufficiently dried smears (and/or smears that are too thick) can detach from the slides during staining. Do not fix thick smears with methanol or heat. If there will be a delay in staining smears, dip the thick smear briefly in water to hemolyse the RBCs.
Why do you avoid the thick area of the smear?
Body and base of the smear These areas are usually too thick to evaluate cells under higher power. The thick area of a smear dries too slowly for leukocytes to spread out.Why are blood smears stained?
These stains allow for the detection of white blood cell, red blood cell, and platelet abnormalities. Hematopathologists often use other specialized stains to aid in the differential diagnosis of blood disorders.How can a blood test detect malaria?
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.Why is smear fixed on a slide?
The purpose of making a smear is to fix the bacteria onto the slide and to prevent the sample from being lost during a staining procedure. A smear can be prepared from a solid or broth medium. Below are some guidelines for preparing a smear for a Gram-stain. of liquid bacterial growth in the center of a clean slide.What is Giemsa stain used for?
It differentially stains human and bacterial cells purple and pink respectively. It can be used for histopathological diagnosis of malaria and some other spirochete and protozoan blood parasites. Giemsa stain is a classic blood film stain for peripheral blood smears and bone marrow specimens.How is Leishman stain prepared?
Preparation of Leishman's Stain solution: Mix and dissolve 0.15 g of Eosin-Methylene blue (Leishman's stain A4277) in 100 ml Methanol dried p.A. (AppliChem product No. A0556) at 56°C. When the stain is dissolved completely remove the solution from the heater. (Alternatively, dissolve at RT over night.What is the principle of romanowsky stain?
Romanowsky stains are neutral stains composed of a mixture of oxidized methylene blue (azure) dyes and Eosin Y. The azures are basic dyes that bind acid nuclei and result in a blue to purple color. The acid dye, eosin, is attracted to the alkaline cytoplasm, producing red coloration.What are the characteristics of a good blood smear?
It should have a rainbow sheen when reflecting light. The smear should be smooth the entire length of the slide with no holes, lines or grainy appearance. The slide consists of a blood smear that is exactly one cell thick in the feathered edge when viewed microscopically.How do you stain malaria parasite?
Thick blood films Field's stain was applied by dipping the slide into Field's stain A for 3 seconds, then into tap water for 3 seconds (with gentle agitation), into Field's stain B for a further 3 seconds and then washing gently in tap water to remove excess stain. The slide was then air dried for at least 30 minutes.How do you stain a thin blood film?
Fix the thin film by dipping it briefly into methanol or poor some drops of methanol on the thin film. When the methanol is evaporated, place the slides in a staining trough (back to back, 20 slides/trough) or on a staining rack (depending on how much slides you have to stain) Do NOT let the slides touch each other.At what angle should you hold the spreader slide to make the smear?
Hold the spreader slide at 30-40 degrees to achieve optimal smear length. Maintain even contact throughout the spreading motion. Short smear • Use a larger droplet of blood. Decrease the angle of the spreader slide.How do you test for malaria?
Diagnosis of malaria involves performing blood smears. For a blood smear, a drop of blood is applied to and spread onto a glass slide. It is then treated with a special stain and examined under a microscope for the morphology of infected blood cells and the parasite.How do you stain thick smears?
Procedure: • Fill staining dish with staining solution • Place thin film and thick films into the staining dish. Stain blood slides for 45 minutes • Wash in water. Dry it and examine under oil immersion lens of the microscope.How do you make a blood slide?
- Place clean glass slide on a flat surface. Add one small drop of blood to one end.
- Take another clean slide, and holding at an angle of about 45 deg, touch the blood with one end of the slide so the blood runs along the edge of the slide by capillary action.
- Make 2 smears, allow to air dry, and label clearly.
