Histopathology Techniques Quiz With Answers

Haematoxylin and eosin (HE) is a commonly used general tissue staining method in histology. Haematoxylin stains the nuclei of cells blue or purple, while eosin stains the cytoplasm and extracellular matrix pink. This staining technique allows for the visualization of cellular structures and tissue architecture, aiding in the identification and differentiation of different cell types and tissue components. HE staining is widely used in pathology and research to study various diseases and conditions, as it provides valuable information about the cellular and structural changes occurring in tissues.

A microtome is a tool used to cut thin sections of tissue for examination under a microscope. It is specifically designed for cutting paraffin-embedded sections of tissue, allowing for precise and controlled slicing. The other options, such as electron beams, sharp knife, and laser, are not commonly used for cutting paraffin-embedded sections and may not provide the same level of accuracy and consistency as a microtome.

Paraffin-embedded sections have the advantage of being able to prepare relatively thin sections from a block of tissue embedded in paraffin. These sections can be stained using various methods, and the microscopic structure of the tissue is well preserved. Additionally, sections and blocks can be activated without any change for decades. However, there are some disadvantages to using paraffin-embedded sections, including tissue shrinkage, inability to detect lipids, and inactivation of enzymes.

Plasmatic Aniline dyes, such as eosin, are acidic and have an affinity for basic tissue structures. Eosin specifically colors structures pinkish, including granules of eosinophilic leukocytes, acidophilic cells in the Pituitary gland, and erythrocytes, which are stained very intensively red. Therefore, the statement that eosin is used in a general tissue staining called Haematoxylin and eosin (HE) is true.

Nucleic (BASIC) stains bind to acidic tissue structures, such as the chromatin of the nucleus, ergastoplasm, and ground substance of the cartilage. These stains can be differentiated based on their variants, such as haemotoxylins and nuclear red, which result in dark or red nuclei, respectively. Basic aniline dyes, like cresyl violet and toluidine blue, stain ergastoplasm in a different shade, known as metachromatically, compared to the nuclei. In Nissl staining, which is used in the nervous system, the nuclei appear greenish blue while the Nissl substance appears reddish.

The correct answer is true because staining sections in histology involves deparaffinizing the sections in xylene to remove the wax, followed by rehydrating the sections through a series of decreasing concentrations of ethanol to remove any remaining alcohol. Finally, the sections are rinsed in distilled water to prepare them for staining. This process ensures that the sections are properly prepared and ready for staining.

Sudan III and IV are commonly used stains for lipid detection. These stains have a high affinity for lipids and can selectively bind to them, allowing for their visualization under a microscope. Sudan III and IV stains are often used in histology and pathology laboratories to identify and study lipid-rich tissues and structures. They can be used to detect lipids in various biological samples, such as cells, tissues, and fluids. Sudan III and IV stains are especially useful in identifying and studying lipid droplets, which are important cellular organelles involved in lipid metabolism.

The temperature of the paraffin the tissue is placed in is 56°C.

Paraffin embedded sections that have been cut are typically around 5-8 uM thick. This is the standard thickness for paraffin sections in histology and pathology laboratories. The thickness is important for obtaining clear and accurate microscopic images of the tissue samples.

The best resolving power is 0.2 uM because it is the smallest value among the given options. Resolving power refers to the ability of an optical system to distinguish between two closely spaced objects or details. In this case, a smaller value indicates a higher resolving power, meaning that the system can distinguish smaller details in the magnified image.

Light microscopy is the correct answer because it is the method used for observing unstained structures in dark field or using phase contrast in tissue cultures. Light microscopy uses visible light to illuminate the sample, allowing for the visualization of structures without the need for staining or other contrast-enhancing techniques. This method is commonly used in biological research and allows for the observation of living cells and tissues in their natural state.

Using thinner resin-embedded sections can achieve better resolution in microscopy because thinner sections allow for clearer imaging and higher magnification. Thicker sections may result in distortion and reduced clarity, making it difficult to observe fine details. By using thinner resin-embedded sections, the microscope can capture more precise and detailed images, enhancing the resolution and overall quality of the microscopy.

Haemotoxylins are a group of dyes that are commonly used in histology to stain the nuclei of cells. These dyes have an affinity for nucleic acids, particularly DNA, and when applied to tissue samples, they bind to the DNA molecules present in the nuclei. The resulting color of the stained nuclei is blue-purple, which is why the correct answer is "Dark blue-purple".

Nissl staining is a method used to stain the cell bodies of neurons in order to study their structure and organization. It specifically stains the Nissl substance, which is mainly composed of ribosomes and rough endoplasmic reticulum. When using Nissl staining, the Nissl substance in the central nervous system (CNS) appears red in color. This staining technique allows researchers to visualize and study the distribution and characteristics of neurons in different regions of the CNS.

The correct answer is "Frozen section". Frozen sectioning is a technique used in histology where tissues are frozen and cut into thin sections for microscopic examination. This method does not require the use of fat solvents, making it a suitable alternative to avoid their use. Paraffin-embedded sectioning, on the other hand, involves embedding tissues in paraffin wax, which may require the use of fat solvents to remove the wax before staining. Therefore, frozen sectioning is the preferred method to avoid the use of fat solvents.

Nissl staining is a histological technique used to visualize the distribution of neurons in the central nervous system (CNS). It specifically stains the rough endoplasmic reticulum in neurons, which appears as granules in the cytoplasm. When using Nissl staining, the nuclei of neurons typically appear greenish blue in color. This is because the stain binds to RNA and DNA, which are abundant in the nucleus of cells. Therefore, the correct answer is greenish blue.

Epoxy resin sections are stained with toluidine blue after being cut with a microtome. Toluidine blue is a basic dye that is commonly used in histology to stain acidic components such as nucleic acids and cartilage. It helps to differentiate different tissue structures and cellular components, making them more visible under a microscope.

Xylen and benzene are the solvents that render the tissue translucent.

The advantage of using frozen sections cut by microtomes is that it allows for the avoidance of using fat solvents. This can be beneficial as fat solvents may have potential harmful effects or interfere with certain staining methods. On the other hand, a disadvantage of using frozen sections cut by microtomes is that it is impossible to prepare thin sections. This limitation may affect the quality and accuracy of the analysis or examination being conducted.

Paraffin embedding has several disadvantages. One of them is that the tissue tends to shrink during the embedding process. This can lead to distortions in the sections and make it difficult to accurately analyze the tissue. Additionally, paraffin embedding does not allow for the detection of lipids, which can be important for certain studies. Lastly, the enzymes in the tissue can become inactivated during the embedding process, which can affect the ability to study enzymatic activity in the tissue.

Luxol blue and cresyl violet are both used to stain myelin sheaths in neurohistology. Luxol blue is a lipophilic dye that selectively stains myelin sheaths blue, allowing for the visualization and study of the myelin sheath structure. Cresyl violet, on the other hand, is a basic dye that stains the Nissl bodies in neurons purple, but it also stains myelin sheaths to a lesser extent. Therefore, both Luxol blue and cresyl violet are commonly used in combination to stain and differentiate myelin sheaths and neuronal cell bodies in neurohistological studies.

The correct answer is Perl's reaction. Perl's reaction is a staining technique used to detect and stain haemosiderin, which is an iron-storage pigment. It involves the use of potassium ferrocyanide and hydrochloric acid to form a blue precipitate with haemosiderin, allowing for its identification and visualization under a microscope. Nuclear red is not used for staining haemosiderin. Best carmine, green trichrome, and Weigert resorcin-fuchsin technique are also not specifically used for staining haemosiderin.

Nuclear red is a basic stain, which means it has a positive charge and can bind to negatively charged structures. It is used to stain reticular fibers, which are a type of connective tissue fibers, and also to stain haemosiderin, which is an iron storage complex found in cells. The basic nature of nuclear red allows it to bind to these structures and help visualize them under a microscope.

Neutral lips are stained with Haematoxylin, Sudan III, and Sudan IV. Haematoxylin is a natural dye that stains nuclei blue, while Sudan III and Sudan IV are fat-soluble dyes that stain lipids red. Therefore, these stains can be used to visualize the cellular components of neutral lips, such as nuclei and lipids.