Why are RBCs bright red and WBC nuclei to be poorly stained when using Wrights stain?
Blood Show
OBJECTIVES: At the end of this laboratory session you should be able to identify the cellular and formed elements in peripheral blood and know their functions. SLIDE FOR THIS LABORATORY: 76. BLOOD COMPONENTS Find a region in the blood smear slide where the RBC's are separated (not overlapping). When studying the blood smear slide, pay close attention to nuclear characteristics, staining patterns, and cell diameter (remember that erythrocytes are usually 7-8 µm in diameter). Use the oil immersion lens to identify each cell type. Slide 76 Peripheral blood smear, Wright's stain. Identify the following components: Erythrocytes Platelets (small blue-purple clusters) LEUKOCYTES Leukocytes (or White Blood Cells) can be divided into two main types: Agranular & Granular. When studying the WBC's, keep in mind the percentages listed below which represent the normal adult leukocyte differential.
AGRANULAR LEUKOCYTES Monocytes
Lymphocytes
GRANULAR LEUKOCYTES Neutrophils
Eosinophils
Basophils
White blood cellsWhite blood cells are much less common than red blood cells. There are five types of white blood cell (leucocyte). These are divided into two main classes
This classification depends on whether granules can be distinguished in their cytoplasm using a light microscope and conventional staining methods). All the white blood cells are able to move like an amoeba, and can migrate out of blood vessels into the surrounding tissues. Note - it is easy to confuse the different leucocytes in blood smears. To identify them, you need to look for the shape of the nucleus, and compare their size, relative to that of a red blood cell. Once you have looked at the examples below - have a go for yourself - click here and see if you can identify the 'mystery' cells. Granulocytes:This shows a neutrophil in a blood smear. The neutrophils are 12-14 µm diameter, and so look bigger than the surrounding red blood cells. There is a single nucleus, which is multilobed, and can have between 2 and 5 lobes. The chromatin in the nucleus is condensed. This means that there isn't protein synthesis. There are few organelles in the cytoplasm. NeutrophilsNeutrophils 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:
Function: They are important in inflammatory reactions. This picture shows an eosinophil in a blood smear. These cells are 12 - 17 µm in diameter - larger than neutrophils, and about 3 times the size of a red blood cell. You can see that eosinophils only have two lobes to their nucleus. These cells have large acidophilic specific granules - these stain bright red, or reddish-purple. These granules contain proteins that are 'destructive' and toxic. EosinophilsEosinophils are fairly rarely found in blood smears - making up 1-6% of the total white blood cells. Function :
Eosinophils are also important in killing parasitic worms. This photo shows a picture of a basophil. They are 14-16 µm in diameter, contain lots of deep blue staining granules (basic) and a bilobed nucleus.The granules contain heparin, histamine and serotonin. prostaglandins and leukotrienes. BasophilsBasophils are the rarest type of white blood cell, making up only 1% of the white blood cells found in a blood smear. Function: Agranulocytes: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. These larger cells have more cytoplasm, more free ribosomes and mitochondria. Lymphocytes can look like monocytes, except that lymphocytes do not have a kidney-bean shaped shaped nucleus, and lymphocytes are usually smaller. Larger lymphocytes are commonly activated lymphocytes. They have a small spherical nucleus and has abundant dark staining condensed chromatin. Not much cytoplasm can be seen, and it is basophilic (pale blue/purple staining). LymphocyteThese are the second most common white blood cell (20-50%), and are easy to find in blood smears. Although the cells look similar there are two main types, B-cells and T-cells. B-cells develop in the bone marrow. T cells are born in the bone marrow, but are matured in the Thymus. There will be more on this in the section on the immune system. Function: This is a photo of a monocyte in a blood smear. These are the largest type of white blood cells, and can be up to 20µm in diameter. They have a large eccentrically placed nucleus, which is kidney bean shaped. They have abundant cytoplasm, and some fine pink/purple granules in cytoplasm. MonocyteMonocytes are the third most common type of white blood cell; about 2-10% of leucocytes are monocytes. Function:
Monocytes are important in the inflammatory response. Why are RBCs bright red and WBC nuclei to be poorly stained when using Wright's stain?Flashcards made directly from the Success! in Clinical Laboratory Science book. How does the Wright's stain help identify white blood cells?Wright's stain is a hematologic stain that facilitates the differentiation of blood cell types. It is classically a mixture of eosin (red) and methylene blue dyes. It is used primarily to stain peripheral blood smears, urine samples, and bone marrow aspirates, which are examined under a light microscope.
When using Wright's stain which type of tissues cells are stained which colors?One of the most commonly used differential stains is the Wright-Giemsa stain, which stains red blood cells a pinkish-red color, and stains the nucleus and cytoplasm of white blood cells various shades of purple.
Which inclusion Cannot be visualized on Wright's stain?Some erythrocyte inclusions cannot be visualized on a Wright or Wright-Giemsa stained smear and require the use of a special stain, such as an iron stain or a supravital stain, to confirm their presence in the erythrocyte.
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