Well-made peripheral smears can be prepared by starting with only a drop of blood at one end of a clean glass slide. The drop is smeared lightly and quickly with a wedge technique so as to leave a thin “feather” edge where all cells may be examined individually, particularly red blood cells.
What are the steps in the preparation of blood smear?
- 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.
How do you prepare a peripheral blood smear write the characteristics of an ideal blood smear?
The smear should occupy the central area of the slide and be margin-free at the edges. Producing a good quality smear requires practice. The blood smear must not be too thin or too thick and the tail of the smear must be smooth. The perfect quality smear is influ- enced by three factors: speed, angle and drop size.
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 is smear preparation?
In a smear preparation, cells from a culture are spread in a thin film over a small area of a microscope slide, dried, and then fixed to the slide by heating or other chemical fixatives. A good smear preparation is the key to a good stain.
Why do we prepare blood smears?
A blood smear, also referred to as a peripheral smear for morphology, is an important test for evaluating blood-related problems, such as those in red blood cells, white blood cells, or platelets.
How do you make a smear?
- Place one needle of solid bacterial growth or two loops. of liquid bacterial growth in the center of a clean slide.
- If working from a solid medium, add one drop (and only one drop) …
- Now, with your inoculating loop, mix the specimen with the water. …
- Place the slide on a slide warmer and wait for it to dry.
What is slide method in blood smear?
Slide Method Procedure Place a drop of blood in the centre of a clean glass slide 1 to 2 cm from one end. Place another slide (spreader) with smooth edge at an angle of 30-45⁰ near the drop of blood. Move the spreader backward so that it makes contact with drop of blood.What is the appropriate sample used for preparing a peripheral blood smear?
Well-made peripheral smears can be prepared by starting with only a drop of blood at one end of a clean glass slide. The drop is smeared lightly and quickly with a wedge technique so as to leave a thin “feather” edge where all cells may be examined individually, particularly red blood cells.
What are the characteristics of a well prepared blood smear?A well made blood smear. The classic blood smear has a thumb print appearance. A well developed feathered edge is apparent. The dense body of the smear takes up most of the slide and there is a thin counting area which blends with the feathered edge and the dense body.
Article first time published onWhat does a peripheral blood smear show?
It evaluates the white blood cells (WBCs, leukocytes), red blood cells (RBCs, erythrocytes) and platelets (thrombocytes). Blood smear is examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.
What are the materials used in blood smear preparation?
- microscope slides with frosted ends for writing on.
- spreader slide – use a specific spreader slide with bevelled edges, or a second clean microscope slide.
- capillary (microhaematocrit) tubes.
- pencil to label the slides.
- blood collected in an EDTA tube.
What is smear in staining procedure?
A bacterial smear is a thin layer of bacteria placed on a slide for staining. Preparing the smear requires attention to a number of details that help prevent contamination of the culture and ensure safety to the preparer.
How do you prepare a fixed smear sample?
In order to heat fix a bacterial smear, it is necessary to first let the bacterial sample air dry. Then either place the slide in the slide holder of a microincinerator, or pass the dried slide through the flame of a Bunsen burner 3 or 4 times, smear side facing up. Once the slide is heat fixed, it can then be stained.
What are the two methods of fixing a smear?
Fixation. The fixation procedure is the same regardless of smear source, plate or broth. There are two methods of adhering your bacteria to the slide, heat fixation or methanol fixation.
What is the importance of heat fixing of prepared smears?
Heat fixing kills the bacteria in the smear, firmly adheres the smear to the slide, and allows the sample to more readily take up stains.
What is dry smear?
A new dry smear-rehydration technic is described. Slides prepared in such a manner invariably contained greater numbers of cellular elements. This method greatly reduces the large “wash-off” loss observed by us (and others) when slides are prepared by wet fixation.
What are the common mistakes in preparing bacterial smear?
- Applying too much bacteria to the slide.
- Not heat fixing the bacteria before staining.
- Wiping off the slides will result in a loss of bacteria present.
What are the important precautions in preparing a blood smear?
- Angle should be maintained at 45°.
- Blood drop should be of proper size.
- Spreader’s edges should be smooth and it should be smaller than the slide on which smear is being made.
- Pressure applied should be proper. …
- Drop should be pulled with spreader not pushed with it.
How do you count platelets in a blood smear?
An estimated platelet count can be done quickly with a blood smear evaluated at 100× magnification. At this magnification, the platelet count/µL of blood can be approximated by multiplying the number of platelets seen in one microscope field by 15,000.
How do you prepare Field stain A and B?
- Fill up two Coplin jars or wide-mouth bottles: …
- Make a blood smear on a clean glass slide, and it is dried in the air.
- Fix in methanol for one minute or get Spray ‘Easyfix’.
- Dry in the air.
- Dip fixed smear to Field Stain B (Red Stain) for 5 to 6 seconds.
How do you calculate WBC on a peripheral smear?
- Choose a one-cell layer area, no overlapping/crowding of cells and count WBCs present in several fields.
- Estimated # of WBCs per ml blood = (average # of WBCs per field x 1000) x 1/4.
What is normal blood smear?
A blood smear is considered normal when your blood contains a sufficient number of cells and the cells have a normal appearance. A blood smear is considered abnormal when there’s an abnormality in the size, shape, color, or number of cells in your blood.
How do you read a blood smear?
- Red blood cell number. First, make sure you’re in the right part of the smear. …
- Red cell size. …
- Red cell shape. …
- Red cell chromasia. …
- Reticulocytes. …
- Stuff inside red cells. …
- Platelet number. …
- Platelet morphology.
How is a spreader selected for making a smear *?
(1) Making a ‘spreader’ slide—a glass slide with absolutely smooth edges should be selected and one or both corners at one end of the slide should be broken off. The ‘spreader’ slide should be narrower (width of about 15 mm) so that edges of the smear can be examined microscopically.
How do you select a spreader slide to prepare a smear?
Push the spreader slide forward along the length of the lower slide. Maintain a constant smooth motion, angle and even contact. Note – blood is being dragged behind the spreader slide, not in front of the slide. An optimal smear is ¾ the length of the slide and has a feathered edge.
Which WBC are granulocytes?
Neutrophils, eosinophils, and basophils are granulocytes. A granulocyte is a type of white blood cell. Also called granular leukocyte, PMN, and polymorphonuclear leukocyte.
What should be done first when creating any new smear slide?
What should be done first when creating any new smear slide? Label the slide with the name of the organism.
How is a wet mount prepared?
A wet mount is made by placing a fluid solution on a slide, suspending a specimen in a solution, and then covering the specimen and the solution with a cover slide. Why would use a wet mount? To increase the specimens translucency and to make it easier to stain.
What is a smear in microbiology?
A bacterial smear is simply that—a small amount of culture spread in a very thin film on the surface of the slide. To prevent the bacteria from washing away during the staining steps, the smear may be chemically or physically “fixed” to the surface of the slide.
What is Gram positive vs gram negative?
Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide. Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.
