"Special stains" are processes that generally employ a dye or chemical that has an affinity for the particular tissue component that is to be demonstrated. They allow the presence/or absence of certain cell types, structures and/or microorganisms to be viewed microscopically. n.
What does affinity mean in chemistry?
Affinity. (1)Often used to describe an attractive force between two molecules or the strength of that force. See also avidity. (2)In a physicochemical context relevant to staining, affinity is the degree to which a reagent (e. g. dye, enzyme substrate, labeled antibodyorsilver ion) transfers from the staining solution into the tissue.
What is staining in biology?
A stain deposited within an opening or against the surface of a cell or tissue, to visualize the morphology or presence of the biological structure. The entity of interest itself is not stained.
What is acid-fast stain?
Acid-Fast Stain- Principle, Procedure, Interpretation and Examples. It is the differential staining techniques which was first developed by Ziehl and later on modified by Neelsen.
What is artifact staining?
The staining of a single cell or tissue component, and no other. Specific stains are much less common than many believe. Even a reagent such as a labeledantibodyoften gives positive artifacts, due to non-immunological staining mechanisms.
What is meant by staining '?
1 : to suffuse with color. 2 : discolor, soil. 3a : taint sense 3 a conscience stained with guilt. b : to bring discredit on the scandal stained his reputation. 4 : to color (something, such as wood, glass, or cloth) by processes affecting chemically or otherwise the material itself.
What is staining in histology?
Staining is a commonly used medical process in the medical diagnosis of tumors in which a dye color is applied on the posterior and anterior border of the sample tissues to locate the diseased or tumorous cells or other pathological cells (Musumeci, 2014).
What is staining in chemistry?
A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials appear used, degraded or permanently unclean.
What is meant by staining in microbiology?
Staining is a technique used in microscopy to enhance contrast in a microscopic image. Stains and dyes are frequently used to highlight structures in microbes for viewing, often with the aid of different microscopes.
What is the purpose of staining?
The purpose of staining is to increase the contrast between the organisms and the background so that they are more readily seen in the light microscope.
What is staining and its types?
TypesSr. No.Staining Technique2.Negative (Relief)3Gram4Acid fast (Ziehl-Neelsen technique)5Endospore (Dornor's method)8 more rows
Which of the following increases the affinity of cells to a dye?
Factors that affect affinity and ultimately staining include the following: Concentration of the dye - The greater the concentration of the dye, the more the dye is bound to tissue components. Temperature - An increase in temperature increases the rate at which the dye diffuses throughout the tissue sample.
What is stain preparation?
In preparation for staining, a small sample of microorganisms is placed on a slide and permitted to air dry. The smear is heat fixed by quickly passing it over a flame. Heat fixing kills the organisms, makes them adhere to the slide, and permits them to accept the stain.
Why is staining used in tissue analysis?
Therefore staining is used to create differential coloration, allowing clearer observation and analysis of cells.
Why is staining important in histology?
Staining is widely used in histopathology and diagnosis, as it allows for the identification of abnormalities in cell count and structure under the microscope. A huge range of stains is used in histology, from dyes and metals to labeled antibodies.
What is the most common histologic stain used to differentiate different tissue structures?
It also plays an important role in the diagnoses of various pathologies. Haematoxylin , is a naturally occurring dye found in Longwood tree wood in Central America. In the H&E stain, a mixture of oxidised hematoxylin known as hematein is used. Due to poor affinity of hematin with tissues, a mordant is incorporated in the H&E stain. Most commonly used mordants are salts of aluminium, iron and tungsten. This substance is known as hemalum. When applied to a tissue section, hemalum stains nuclei blue. The sample is then counterstained using a solution of eosin (either alcohol or water), which stains proteins and cytoplasm varying shades of pink. Eosin are xanthene dyes and have different types, but generally Eosin Y is commonly used.
What is the EOSIN Y?
Eosin are xanthene dyes and have different types, but generally Eosin Y is commonly used. Haematoxylin & Eosin stain of the loose connective tissue (histological slide) The general procedure of the H & E stain is as follows: The section is rehydrated and then cleared using xylene.
Why is a saline stain used in the diagnosis of many diseases?
It stains human and pathogenic cells differently, therefore, it is used in the diagnosis of many diseases as it stains human cells purple, and bacterial cells pink, so that they may be differentiated. It is also used to stain blood cells, so that their composition and structure may be observed.
Why is blood stain used in histology?
It was later used in histology because of its high quality staining capabilities of chromatin and nuclear membranes. It stains human and pathogenic cells differently, therefore, it is used in the diagnosis of many diseases as it stains human cells purple, and bacterial cells pink, so that they may be differentiated. It is also used to stain blood cells, so that their composition and structure may be observed.
What is the purpose of the Wright and Wright stain?
The eosin Y is then used to stain cell cytoplasm orange. Both of them are used to stain peripheral blood smear and bone marrow smears. They are used to look at cells as well as their morphology, aiding in the diagnosis of infections and blood diseases such as leukemia. Different blood cell types become stain differently allowing them to be differentiated by the observer.
Who developed acid fast staining?
Acid-Fast Stain- Principle, Procedure, Interpretation and Examples. It is the differential staining techniques which was first developed by Ziehl and later on modified by Neelsen. So this method is also called Ziehl-Neelsen staining techniques. Neelsen in 1883 used Ziehl’s carbol-fuchsin and heat then decolorized with an acid alcohol, ...
What is the name of the staining method used by Neelsen?
So this method is also called Ziehl-Neelsen staining techniques. Neelsen in 1883 used Ziehl’s carbol-fuchsin and heat then decolorized with an acid alcohol, and counter stained with methylene blue. Thus Ziehl-Neelsen staining techniques was developed.
How long does carbol fuchsin stain stay on slide?
Allow the heated stain to remain on the slide for 5 minutes. Heating the stain: Great care must be taken when heating the carbol fuchsin especially if staining is carried out over a tray or other container in which highly fiammable chemicals have collected from previous staining.
Why are non-acid fast cells colorless?
The non-acid fast organism lack the lipoidal material in their cell wall due to which they are easily decolorized, leaving the cells colorless. Then the smear is stained with counterstain, methylene blue. Only decolorized cells absorb the counter stain and take its color and appears blue while acid-fast cells retain the red color.
How to acid fast stain a sputum?
Procedure of Acid-Fast Stain. Prepare bacterial smear on clean and grease free slide, using sterile technique. Allow smear to air dry and then heat fix. Alcohol-fixation: This is recommended when the smear has not been prepared from sodium hypochlorite (bleach) treated sputum and will not be stained immediately.
How to clean a malachite smear?
Caution: Acid alcohol is fiammable, therefore use it with care well away from an open fiame. Wash well with clean water. Cover the smear with malachite green stain for 1–2 minutes, using the longer time when the smear is thin. Wash off the stain with clean water.
Which microorganisms are not stainable by simple or Gram staining?
This method is used for those microorganisms which are not staining by simple or Gram staining method, particularly the member of genus Mycobacterium, are resistant and can only be visualized by acid-fast staining.
