Exam 1 Nuclear And Cytoplasmic Staining

In the methyl green-pyronine stain, the DNA is stained green. This staining technique involves the use of methyl green, which binds to DNA molecules and imparts a green color. Pyronine, on the other hand, is used to counterstain other cellular components, such as RNA, which appear red. Therefore, the correct answer is green.

Giemsa stain is commonly used on bone marrow smears to identify white blood cells (WBC). Giemsa stain is a combination of methylene blue and eosin dyes, which selectively stain different components of cells. It is particularly useful for identifying different types of blood cells, including WBCs, by staining their nuclei and cytoplasm. The stain helps in distinguishing different types of WBCs based on their morphology, size, and staining characteristics.

Ripening of hematoxylin refers to the process of oxidizing the dye molecule to enhance its staining properties. Oxidation involves the loss of electrons or an increase in the oxidation state of an atom, which in this case results in the hematoxylin molecule becoming more reactive and capable of binding to cellular components for better staining. This process is important in histology and pathology laboratories where hematoxylin is commonly used as a staining agent to visualize cell nuclei.

Mordants are substances that are used to enhance the attraction between tissue and dye. They form a chemical bond with both the tissue and the dye, creating a stronger and more permanent attachment. This allows the dye to adhere more effectively to the tissue, resulting in better staining and improved visibility of cellular structures. By enhancing the tissue/dye attraction, mordants help to ensure accurate and clear staining in histological procedures.

Hematoxylin is extracted from logwood trees. Logwood trees, scientifically known as Haematoxylum campechianum, are native to Central America and the Caribbean. The heartwood of these trees contains a natural dye called hematoxylin, which is extracted and used in various applications, including histology and staining techniques in biology and medicine. This dye has a deep blue color and is commonly used in combination with eosin to stain different types of cells and tissues for microscopic examination.

Under alkaline conditions, methylene blue undergoes a chemical reaction that results in the formation of two distinct dyes called azure A and B.

Basophilic refers to substances that have an affinity for basic dyes and are attracted to the acidic components of cells. Nucleic acids, including RNA and DNA, contain phosphate groups that are negatively charged and acidic. These acidic phosphate groups attract basic dyes, making nucleic acids basophilic. Therefore, the correct answer is basophilic.

Gills III is the correct answer because it is a hematoxylin solution specifically designed to stain mucin. Mucin is a glycoprotein found in goblet cells, which are specialized cells found in the epithelial lining of various organs, including the respiratory and digestive tracts. Gills III is formulated to selectively bind to mucin, allowing for its visualization under a microscope. The other options, Gills IV, Gills II, and Gills I, are not specifically designed for staining mucin and therefore would not be effective in staining the mucin found in goblet cells.

Adding acetic acid to Harris hematoxylin can make nuclear staining more specific. Acetic acid helps to increase the selectivity of the stain, allowing it to specifically bind to the nuclei of cells. This improves the clarity and visibility of the nuclear staining, making it easier to distinguish and analyze the cellular structures under a microscope.

Harris hematoxylin is converted into a dye lake by adding ammonium aluminum sulfate. The addition of ammonium aluminum sulfate helps to form a stable complex with the hematoxylin dye, resulting in the formation of a dye lake. This dye lake is insoluble and can bind to the target tissue, allowing for better staining and visualization of cellular structures. The other options, sodium iodate, ferric chloride, and citric acid, do not have the same effect on the conversion of Harris hematoxylin into a dye lake.

Eosin is classified as an anionic dye because it carries a negative charge when dissolved in water. Anionic dyes are attracted to positively charged surfaces, making them useful for staining negatively charged structures such as cell nuclei. Eosin is commonly used in histology to stain cytoplasm and extracellular structures, as it is readily taken up by acidic components. Therefore, the correct answer is anionic dye.

A stain which has methylene blue and eosin is known as a Romanowsky stain. This type of stain is commonly used in medical laboratories for the staining of blood smears. The combination of methylene blue and eosin allows for the differentiation of various cellular components in the blood, such as red blood cells and white blood cells. The Romanowsky stain technique was developed by Russian physician Romanowsky in the late 19th century and has since become a widely used staining method in hematology.

The Feulgen reaction is unsatisfactory on tissue that was fixed in Bouin solution. Bouin solution is a fixative that contains picric acid, formaldehyde, and acetic acid. The picric acid in Bouin solution can interfere with the Feulgen reaction, leading to unsatisfactory results. Therefore, tissue fixed in Bouin solution is not suitable for the Feulgen reaction.

Protein molecules are considered amphoteric in nature because they can act as both acids and bases. This is due to the presence of both positively and negatively charged free side chains in their structure. These charged side chains can form biochemical bonds through electrostatic interactions with other molecules, allowing proteins to participate in a wide range of chemical reactions and interactions in biological systems.

Powdered dyes consist of two main molecular components. The component responsible for providing color is called the chromophore. The chromophore is the part of the molecule that absorbs and reflects certain wavelengths of light, resulting in the perception of color. The other options, auxochrome, autochrome, and chromeophore, are not correct as they do not accurately describe the component responsible for conferring color in powdered dyes.

When Harris hematoxylin is used at full strength without acetic acid added, the intended mode of staining is regressive. In regressive staining, the excess stain is removed from the tissue sections, resulting in a more intense and specific staining of the target structures. This method is commonly used in histology to enhance the visibility of cellular components and tissue structures.

When tissues are exposed to acid solutions, the acid dissociates into hydrogen ions (H+). These hydrogen ions can bind to negatively charged molecules in the tissues, causing them to become positively charged. Therefore, the correct answer is "positively charged."

Electrostatic bonding is the most common method of biochemical bonding between tissue proteins and dyes. This type of bonding occurs when there is an attraction between positively and negatively charged particles. In the case of tissue proteins and dyes, the proteins may have charged regions that can interact with the charged regions of the dyes, leading to the formation of electrostatic bonds. This type of bonding is important in various biological processes, such as protein-protein interactions and enzyme-substrate interactions.

Synthetic resins are preferred over natural resins because they have a neutral pH, which means they are neither acidic nor alkaline. This is important because acidic or alkaline resins can cause damage to the stained material over time. Additionally, synthetic resins are able to preserve the intensity of the stain over time, ensuring that the colors remain vibrant and do not fade. This makes them a better choice for long-term preservation of stained materials.

Weigert hematoxylin stain will best resist decolorization because it is specifically designed to be resistant to acid decolorization. This stain is commonly used in histology to stain connective tissue and muscle fibers. The other options, Delafield, Harris, and Mayer's hematoxylin stains, are not specifically formulated to resist decolorization and may be more susceptible to fading or loss of color during the staining process.

The correct answer is that the oxidizing capability of ferric chloride breaks down the dye's hematein content. This is because ferric chloride acts as an oxidizing agent, causing the breakdown of the hematein content in the Weigert hematoxylin solution.

Bouin's fixative is known to cause over fixation, which can result in the impairment of nuclear detail. Over fixation occurs when the tissue is exposed to the fixative for too long or at a high concentration, leading to excessive cross-linking of proteins and DNA, making it difficult to visualize the nuclear structures. This can result in a loss of nuclear detail and hinder the ability to study cellular morphology or identify specific nuclear features.

The active staining ingredient in ripened hematoxylin solutions is aluminum-hematein lake. This is because hematein is the oxidized form of hematoxylin, and it forms a complex with aluminum ions to create a stable staining compound. Sodium iodate is not involved in the staining process and is therefore not the correct answer.

Phloxine B is commonly added to eosin to enhance its differential staining intensity.

Formalin is a fixative commonly used in histology to preserve tissues for microscopic examination. It works by cross-linking proteins in the tissue, including amino groups. This cross-linking process can affect the staining properties of the tissue. Basophilic staining refers to the affinity of certain structures in the tissue to basic dyes like eosin. The statement suggests that formalin, by cross-linking to amino groups, reduces the intensity of eosin staining, indicating that the tissue becomes less basophilic. Therefore, the correct answer is basophilic.

The Feulgen Technique is a method used to differentially stain DNA in the nucleus from all other chromatic proteins. This technique involves treating the cells with hydrochloric acid, which breaks down the DNA into its constituent nucleotides. Then, a Schiff reagent is applied, which reacts specifically with the deoxyribose sugar in the DNA. This reaction results in a purple coloration of the DNA, allowing it to be distinguished from other proteins in the nucleus.

The isoelectric point (IEP) of a protein is the pH at which the protein has no net charge. At a pH below its IEP, the protein carries a net positive charge, while at a pH above its IEP, it carries a net negative charge. Therefore, the IEP of a protein in tissue is pH 6, indicating that at this pH, the protein is uncharged.

Dyes need an ionized group in order to bind to tissue. This ionized group is known as an auxochrome.

Eosin is an acidic dye and it stains tissue components that are positively charged, such as cytoplasm and extracellular matrix. When the pH becomes too alkaline, the tissue becomes more negatively charged, which repels the negatively charged eosin dye. As a result, the staining intensity decreases.

The -NH group is not an example of an Acid Dye ionic group. Acid dyes are typically anionic, meaning they have a negative charge. The -NH group is neutral and does not carry a charge. The other options, -SO4, -COOH, and -OH, are all examples of anionic groups commonly found in acid dyes.

Most cytoplasmic proteins are acidophilic, meaning that they have a strong affinity for acidic dyes. This is because the cytoplasm of cells tends to have a slightly acidic pH, and the proteins within the cytoplasm are adapted to function optimally under these conditions. Acidophilic proteins are able to interact with acidic dyes, allowing for their visualization and study in laboratory settings.

Before the introduction of immunohistochemical techniques, methyl green-pyronine was primarily used to identify plasma cell tumors. This staining method allowed for the visualization of the characteristic morphology and staining properties of plasma cells, which are the cells involved in plasma cell tumors. Methyl green-pyronine staining helped in distinguishing plasma cell tumors from other types of tumors or conditions, aiding in their diagnosis and classification.

Restaining the slide with Weigert iron hematoxylin can enhance pale nuclear staining of over decalcified bone. This method involves using a specific type of hematoxylin stain, Weigert iron hematoxylin, which has a higher affinity for the nuclei of cells. By restaining the slide with this stain, the nuclei in the decalcified bone can be more clearly visualized and enhanced, resulting in a stronger and more distinct nuclear staining.

Hydrochloric acid is known to hydrolyze DNA in the Feulgen technique. Hydrolysis is a chemical reaction that breaks down molecules by adding water. In this case, hydrochloric acid reacts with the DNA, causing its decomposition into smaller fragments. This process is essential in the Feulgen technique, as it helps to expose the DNA's sugar-phosphate backbone, allowing for the subsequent staining and visualization of the DNA.

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Excess mordant, ferric chloride is used to differentiate the tissue and clearly demonstrate the elastic fibers. The mordant helps to bind the stain to the tissue and enhance the contrast between the elastic fibers and the surrounding tissue. By using excess ferric chloride, the staining of the elastic fibers is intensified, making them more visible under the microscope. This allows for a better identification and examination of the elastic fibers in the tissue sample.