Histopathology Techniques Quiz Questions And Answers

Xylene is commonly used as an agent for removing alcohol and making tissue transparent. It is a clear, colorless liquid that has the ability to dissolve alcohol and other substances, allowing for the dehydration and clearing of tissues. Xylene is frequently used in histology laboratories for processing tissue samples before embedding them in paraffin wax. It helps to remove any remaining water and alcohol from the tissues, making them transparent and ready for further processing and staining.

This statement is true because the concentration of a stain refers to the amount of the stain present in a given volume of solution. When the concentration of the stain is higher, there are more stain molecules available to interact with the solvent molecules. This increases the likelihood of ionization, which is the process of forming ions by gaining or losing electrons. Therefore, the higher the concentration of the stain, the more the ionization.

Mounting is the correct answer because it refers to the process of placing a specimen onto a slide and covering it with a coverslip. This step is essential for easy handling and storage of the specimen, as it protects it from damage and allows for easy examination under a microscope. The other options, such as deparaffinization, hydration, dehydration, and clearing, are all steps involved in the preparation of the specimen before mounting.

Harris hematoxylin is a commonly used stain in histology and microscopy. A mordant is a substance that enhances the binding of a dye to the target tissue or structure. In the case of Harris hematoxylin, the mordant used is K alum, which helps to intensify the staining of nuclei. Therefore, the statement that the mordant in Harris hematoxylin is K alum is true.

An increase in temperature actually speeds up the rate of penetration. This is because higher temperatures increase the kinetic energy of molecules, leading to faster diffusion and reaction rates. As a result, the molecules are able to move more quickly and penetrate more easily. Therefore, the statement that an increase in temperature slows the rate of penetration is incorrect.

The principles of histological technique for distinction of tissue components are based on both alteration of contrast and alteration of color. Alteration of contrast involves enhancing the differences in intensity between different tissue components, making them easier to distinguish. Alteration of color involves using stains or dyes to selectively color different tissue components, highlighting their differences in color. By combining these two principles, histological techniques can effectively differentiate between different tissue components.

Dyes and stains are both essentially aromatic benzene ring components and possess the properties of color and ability to bind to tissue. This means that they are capable of providing color to substances and have the ability to bind to tissues, making them useful in various applications such as coloring fabrics or staining biological samples for microscopic examination.

Hematoxylin is a dye commonly used in histology to stain the nucleus of cells. It has an affinity for DNA and RNA, allowing it to bind and color the nucleus. The other options, staining the cytoplasm and being negatively charged, are incorrect as hematoxylin specifically targets the nucleus. Therefore, the correct answer is that hematoxylin stains the nucleus.

Thionine is classified as a thiazine dye because it contains a thiazine ring structure in its chemical composition. Thiazine dyes are a class of synthetic dyes that are commonly used in various applications such as textile dyeing, biological staining, and as sensitizers in photography. Thionine, specifically, is a blue-violet dye that is often used in histology to stain cell nuclei.

Regressive staining is the correct answer because it refers to a staining technique where the excess stain is removed from the tissue, resulting in a lighter color. This process is commonly used in histology to highlight specific features of the tissue. Decolorization, which is mentioned in the association, is a key step in regressive staining. Progressive staining, on the other hand, involves intensifying the stain by leaving it on the tissue for a longer period.

The correct answer is 2 or 3 changes of xylene for 1 minute. This step is necessary in the clearing process to remove any remaining alcohol and prepare the specimen for embedding in a medium such as paraffin. Xylene is a common clearing agent used in histology to dehydrate and remove alcohol from tissue samples. Multiple changes of xylene ensure thorough clearing and optimal preservation of the tissue. The duration of 1 minute is typically sufficient for the xylene to effectively clear the specimen.

Excess xylene, a common solvent used in histology and microscopy, can cause the formation of bubbles on a slide. This is because xylene has a low surface tension, meaning it does not easily spread out and form a smooth layer on the slide. Instead, it tends to form small droplets that can trap air and create bubbles. Therefore, the statement "Excess xylene favors bubbles on the slide" is true.

Janus green is a vital stain that is commonly used to stain mitochondria in cells. Vital stains are dyes that can selectively stain specific structures or organelles within cells. In the case of Janus green, it has an affinity for mitochondria and can specifically stain these organelles. This staining allows researchers to visualize and study the morphology and function of mitochondria within cells. Therefore, the correct answer for this question is mitochondria.

Mounting is the process of placing a tissue sample onto a microscope slide using a mounting medium. This medium is chosen to have a refractive index (Rf) similar to that of the slide and the tissue, which helps to minimize the distortion of the tissue components and provides a clear visualization. By mounting the tissue, it is securely attached to the slide and can be easily observed under a microscope.

The integral component of a dye that is responsible for altering light resonance is known as a chromophore. A chromophore is a chemical group or moiety within a molecule that absorbs certain wavelengths of light and gives the dye its characteristic color. It is the presence of the chromophore that allows the dye to interact with light and produce the desired color. An auxochrome, on the other hand, is a functional group that modifies the color of the chromophore but is not essential for altering light resonance. Therefore, the correct answer is Chromophore.

An alkaline pH will accelerate the ripening/oxidation process of hematoxylin, causing it to oxidize more rapidly. This means that the color change or staining effect produced by hematoxylin will occur at a faster rate when the pH is alkaline compared to other pH levels.

Direct staining refers to a staining technique where the dye is applied directly to the specimen, without any prior treatment or fixation. In this case, staining with a simple aqueous or alcoholic solution like Methylene Blue is an example of direct staining because the dye is directly applied to the specimen without any additional steps. This technique is commonly used in microbiology to visualize microorganisms under a microscope.

von Apathy's gum syrup is a type of adhesive that is commonly used in microscopy for creating temporary mounts. Temporary mounts are prepared when the specimen is not required to be preserved for a long period of time. The gum syrup provides a temporary adhesive medium that allows the specimen to be easily mounted and observed under a microscope. It can be easily removed or dissolved when the observation is complete, making it suitable for temporary use.

Acid fuchsin is a counterstain that is known for coloring tissues and cells in a magenta shade. Counterstains are used in microscopy to provide contrast and enhance the visibility of certain structures or components. In this case, acid fuchsin is specifically chosen for its ability to produce a magenta color, which helps to differentiate and highlight specific elements in the sample being observed.

Artificial dyes are classified as coal tar dyes, aniline dyes, and derived from the hydrocarbon benzene. This means that all of the options listed in the answer are correct. Artificial dyes can be obtained from coal tar, which is a byproduct of coal processing. Aniline dyes are synthetic dyes derived from aniline, a chemical compound derived from benzene. Therefore, artificial dyes can be both coal tar dyes and derived from the hydrocarbon benzene.

Eosin is commonly used as a stain in histology and microscopy. It is used to enhance the visibility of certain structures and tissues under a microscope. The concentration of eosin used is typically between 0.5-1%. This concentration range provides optimal staining results without causing excessive background staining or distortions in the tissue samples. Using a higher concentration could lead to oversaturation and loss of detail, while a lower concentration may not provide enough contrast for clear visualization. Therefore, a concentration of 0.5-1% is considered suitable for most staining purposes.

Iron mordants are used in histological staining, typically in conjunction with hematoxylin, to create a stable dye complex that primarily stains nuclei, giving them a black or dark blue color. The use of iron mordants in staining focuses on enhancing the dye's affinity for nucleic acids, like DNA and RNA, allowing for precise visualization of cell nuclei. However, iron mordants do not generally stain the cytoplasm black. The cytoplasm typically remains unstained or takes on a different color, depending on the staining protocol used. Therefore, the statement that iron mordants stain the cytoplasm black is incorrect; their primary function is to target nuclear material for staining.

The substances sodium iodate, mercuric oxide, potassium permanganate, and calcium hypochlorite are chemical oxidizing agents, commonly used to induce oxidation reactions. These compounds are known for their ability to react with other chemicals to remove electrons, leading to oxidation. Peroxidase, on the other hand, is an enzyme that catalyzes the oxidation of specific substrates using hydrogen peroxide. While it has oxidizing properties, it belongs to a different category because it is a biological enzyme, not a chemical oxidizing agent. Its function is more specific and biologically oriented compared to the other chemicals listed. Thus, peroxidase does not belong to the same group as the other oxidizing agents.

The association "Kleermount" suggests a specific type of mounting medium used for a particular purpose. The term "synthetic resinous" indicates that the mounting medium is made from synthetic materials, specifically resins. This type of mounting medium is commonly used in laboratories and scientific settings for mounting specimens or slides. The term "natural resinous" refers to mounting mediums made from natural resins, which are less commonly used in scientific applications. Therefore, the correct answer is "synthetic resinous mounting medium" as it aligns with the association and its common usage.

Glacial HAc, or glacial acetic acid, is the component substance in Harris Hematoxylin that is not a mordant but increases staining intensity. It acts as a solvent and helps to enhance the staining process by increasing the penetration of the dye into the tissue.

The optimum pH refers to the specific pH level at which an enzyme or other biological molecule functions most effectively. It does not necessarily indicate that each molecule has an equal number of positive (+) and negative (-) charges. The term describing a pH where a molecule has an equal number of positive and negative charges is the isoelectric point (pI). At the isoelectric point, a molecule, such as a protein, has no net charge. This is different from the optimum pH, which is related to the conditions under which a molecule, like an enzyme, exhibits maximum activity or stability. Thus, the statement that the optimum pH is where each molecule has an equal number of positive and negative charges is incorrect. The correct term for that description is isoelectric point.

Cresyl fast violet contains quinone imine groups. Quinone imine groups are a type of chemical structure that contain both a quinone and an imine functional group. Therefore, cresyl fast violet can be categorized as an example of quinone imine groups.

The statement suggests that blotting should be thoroughly done to dry up the section. However, the correct answer is False because blotting is not used to dry up a section. Blotting is a technique used to transfer substances from one surface to another, typically done to remove excess liquid or to separate components of a mixture.

Both water soluble mounting medium and aqueous mounting medium can be associated with Kaiser's glycerol jelly. This suggests that Kaiser's glycerol jelly can be used as a mounting medium that is both water soluble and aqueous.

An accelerator is a non-mordant substance that increases the rate of staining reaction but does not form a "lake". This means that it helps to speed up the staining process without causing the dye to bind permanently to the material being stained, resulting in a "lake" formation.

Congo red is a synthetic dye that belongs to the class of azo dyes. Azo dyes are a type of synthetic dyes that contain one or more azo groups (-N=N-) in their chemical structure. Since Congo red is a synthetic dye and also an azo dye, the correct answer is "both".

: When using Heidenhain's Iron Hematoxylin, the staining process typically involves separate applications of mordant and stain solution at different stages. It does not involve mixing equal volumes of the mordant solution and stain solution. Heidenhain's Iron Hematoxylin uses a specific staining protocol where the mordant is applied separately to prepare the tissue for staining, followed by the hematoxylin solution, which binds to the tissue through the mordant. Mixing the mordant and stain solutions could disrupt the staining process and lead to undesirable results. The key to Heidenhain's Iron Hematoxylin staining is the sequence and timing of applying the mordant and stain solutions to achieve precise and controlled staining, typically focusing on cell nuclei.

Glacial HAc in hematoxylin acts as an accentuator. In staining techniques, accentuators are used to intensify the color of the dye or stain. In this case, glacial HAc enhances the staining properties of hematoxylin, which is commonly used in histology to stain cell nuclei. It helps to produce a more vivid and distinct staining of the target structures, aiding in their identification and analysis under a microscope.

The optimum pH of Eosin is 5.4-5.6. This means that Eosin exhibits its maximum effectiveness or activity at a pH range of 5.4-5.6. At this pH range, Eosin will have the highest solubility and will be most stable, resulting in the best performance for its intended purpose.

The correct answer is "all of the above." Deparaffinization is a process used in histology to remove paraffin wax from tissue sections before staining. This is done to allow the stain to penetrate the tissue effectively. The deparaffinization process typically involves multiple changes of alcohol, including the use of 95% ethanol, which is a highly organic solvent. Therefore, all of the given statements are true for deparaffinization.

Hydration is the correct answer because it involves the addition of water or an aqueous solution to the tissue sections, which helps to restore their natural state and remove any dehydrating agents. This process prevents rapid movement of fluid into and out of the tissue sections, ensuring that the tissue remains hydrated and intact during subsequent steps of the procedure.

Mallory's hematoxylin stain does not have hematoxylin and a mordant mixed in one solution. The stain is a two-step process where hematoxylin is applied first, followed by a separate mordant solution. This allows for better control over the staining process and enhances the specificity of the stain. In contrast, the other options mentioned (Harris', Ehrlich's, Delafield's, and Weigart's) are all examples of hematoxylin stains that have both hematoxylin and a mordant combined in one solution.

Eosin is an acidified counterstain that is commonly used in histology and microscopy. It gives a good result before its pH rises, indicating that it remains effective for a certain period of time. The correct answer, 2 weeks, suggests that eosin can maintain its acidic properties and provide accurate staining for up to 2 weeks before its pH starts to increase. This means that it can be used reliably for staining purposes within this timeframe, ensuring accurate and consistent results.

Eosin is a commonly used dye in the field of histology and microscopy. It is available in different types, including eosin Y and eosin B. The question specifically asks for the commonly used kind of eosin, and the correct answer is eosin Y. Additionally, eosin Y is described as yellowish in color, which further supports its identification as the commonly used kind of eosin.

Formalin fixative increases the affinity of chemical compounds for basic stains. This means that when tissues or cells are treated with formalin fixative, they become more likely to bind to basic dyes, resulting in a stronger and more visible staining. This is an important step in histology and pathology, as it helps to enhance the contrast and visibility of cellular structures under a microscope.

Fixation treatment of tissues can cause both increased and decreased rates of penetration. Fixation involves the use of chemicals to preserve and stabilize tissues for further analysis. Some fixation methods, such as formalin fixation, can cause tissue shrinkage and hardening, which can decrease the rate of penetration of subsequent reagents or stains. On the other hand, fixation can also increase the rate of penetration by improving tissue permeability and allowing better diffusion of reagents. Therefore, depending on the specific fixation method and conditions, both increased and decreased rates of penetration can occur.

EOSIN is classified as a xanthene dye. Xanthene dyes are a type of synthetic dye that are characterized by their xanthene ring structure. They are commonly used as fluorescent dyes in various applications, including microscopy and histology. EOSIN, specifically, is a red dye that is often used as a counterstain in histological staining procedures. It is known for its ability to stain cytoplasm and extracellular connective tissue, making it useful for highlighting specific structures in tissue samples.

Crystal violet is classified as a triphenylmethane dye. Triphenylmethane dyes are a class of synthetic dyes that contain a central triphenylmethane structure. Crystal violet is a dark green powder that is commonly used as a biological stain and as a dye in various industries. Its triphenylmethane structure gives it its characteristic color and chemical properties, making it suitable for a range of applications.

Staining is a process that renders the different tissue components more visible through variation in color. This is achieved by using dyes and stains, which promote easier optical differentiation. Sensitivity is not a characteristic of successful staining, as it refers to the ability to color one component while leaving others unstained. The statement about hypochromic characteristic for neoplastic and malignant cells is not true, as staining does not specifically show this characteristic.

In histology, both progressive and regressive staining methods result in the dye creating visible colors in the tissue. The association that dye will not be the color seen in the tissue does not align with these staining methods. Progressive staining involves controlled application to achieve the desired color, while regressive staining includes an additional step to remove excess dye. Both methods ultimately create a specific coloration in the tissue, making the association incorrect for these techniques.

The staining done in Reticulocyte count is an example of vital staining because it involves staining living cells to observe their structure and function. It is also an example of supravital staining because it requires staining cells that have been removed from the body and are still viable.

If a drop of hematoxylin is added to water and the solution turns red-brown, it means there is a disproportionate amount of hematoxylin and hematein. Hematoxylin is a natural dye that is extracted from the logwood tree and is commonly used in histology for staining nuclei in tissues. Hematein, on the other hand, is an oxidation product of hematoxylin. When hematoxylin is fresh and in its active form, it appears colorless to yellowish in solution. However, over time, hematoxylin oxidizes to form hematein, which imparts a red-brown color to the solution. A red-brown color indicates that the hematoxylin has undergone oxidation, resulting in a mixture of hematoxylin and hematein that is not in the ideal proportion for staining purposes. In this case, options A and B from the given choices would be correct, as they suggest that the stain is not effective and there is a disproportionate amount of hematoxylin and hematein present in the solution.

Brilliant cresyl blue is classified as an oxazine dye. Oxazine dyes are a type of synthetic dye that contain an oxazine ring structure. These dyes are commonly used in various applications such as textile dyeing, ink manufacturing, and biological staining. Brilliant cresyl blue specifically is often used in medical laboratories for staining blood cells, particularly reticulocytes, to aid in their identification and analysis.