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Questions and Answers
What is the primary purpose of mucin stains in tissue examination?
What is the primary purpose of mucin stains in tissue examination?
What does a calcium stain primarily detect in tissue samples?
What does a calcium stain primarily detect in tissue samples?
Which stain would be most appropriate for identifying excess glycogen in liver tissues?
Which stain would be most appropriate for identifying excess glycogen in liver tissues?
What is the main limitation of using fat stains like Oil Red O?
What is the main limitation of using fat stains like Oil Red O?
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Melanin stains are specifically useful for which of the following?
Melanin stains are specifically useful for which of the following?
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Which tissue components are primarily highlighted by trichrome stains?
Which tissue components are primarily highlighted by trichrome stains?
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What is the significance of detecting hemosiderin through special stains?
What is the significance of detecting hemosiderin through special stains?
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In what context is a fat stain, like Oil Red O, particularly useful?
In what context is a fat stain, like Oil Red O, particularly useful?
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Which of the following options is NOT considered a type of special stain listed?
Which of the following options is NOT considered a type of special stain listed?
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What kind of samples are necessary for accurate fat staining procedures?
What kind of samples are necessary for accurate fat staining procedures?
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What is the primary purpose of glycogen stains in histology?
What is the primary purpose of glycogen stains in histology?
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Calcium stains in histology are primarily used to identify what?
Calcium stains in histology are primarily used to identify what?
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Melanin stains are specifically designed to visualize which type of cellular component?
Melanin stains are specifically designed to visualize which type of cellular component?
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Mucin stains are utilized in histology primarily to identify what?
Mucin stains are utilized in histology primarily to identify what?
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What type of tissues would fat stains be most relevant for?
What type of tissues would fat stains be most relevant for?
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Why are special stains required in histology rather than routine stains?
Why are special stains required in histology rather than routine stains?
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Which of the following is NOT a type of special stain mentioned?
Which of the following is NOT a type of special stain mentioned?
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Which component primarily binds with eosin during staining?
Which component primarily binds with eosin during staining?
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What key feature distinguishes progressive stains from regressive stains?
What key feature distinguishes progressive stains from regressive stains?
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What is the role of a mordant in the staining process?
What is the role of a mordant in the staining process?
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Which stain is specifically used to visualize deposits of calcium or calcium salts in tissue sections?
Which stain is specifically used to visualize deposits of calcium or calcium salts in tissue sections?
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What is the main pathological condition associated with the presence of melanin in tissues?
What is the main pathological condition associated with the presence of melanin in tissues?
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Which special stain is primarily used to detect mucin in tissue?
Which special stain is primarily used to detect mucin in tissue?
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What type of pigmentation is lipochrome associated with?
What type of pigmentation is lipochrome associated with?
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Which staining method can potentially highlight fat within tissues?
Which staining method can potentially highlight fat within tissues?
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Which stain would you use to visualize pathological glycogen accumulation?
Which stain would you use to visualize pathological glycogen accumulation?
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In which anatomical areas is lipochrome pigmentation most commonly found?
In which anatomical areas is lipochrome pigmentation most commonly found?
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What color represents calcium deposits when visualized with H&E stain?
What color represents calcium deposits when visualized with H&E stain?
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Which method utilizes silver nitrate to visualize calcium deposits as black colored spots?
Which method utilizes silver nitrate to visualize calcium deposits as black colored spots?
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What type of tissue change can mucin staining detect?
What type of tissue change can mucin staining detect?
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Which stain is primarily used to detect acidic mucin in tissue samples?
Which stain is primarily used to detect acidic mucin in tissue samples?
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What is the main purpose of the periodic acid-schiff (PAS) reaction?
What is the main purpose of the periodic acid-schiff (PAS) reaction?
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Which statement accurately describes Best's carmine stain?
Which statement accurately describes Best's carmine stain?
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In which type of cancer is the periodic acid-schiff staining particularly useful?
In which type of cancer is the periodic acid-schiff staining particularly useful?
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What characteristic distinguishes neutral mucin from acidic mucin in staining properties?
What characteristic distinguishes neutral mucin from acidic mucin in staining properties?
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Which of the following stains would best demonstrate fat within tissue samples?
Which of the following stains would best demonstrate fat within tissue samples?
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How does the hexamine silver technique primarily identify glycogen in tissues?
How does the hexamine silver technique primarily identify glycogen in tissues?
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Which of the following tissues is most likely to require special staining for melanin detection?
Which of the following tissues is most likely to require special staining for melanin detection?
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What type of carcinomas can be diagnosed using staining techniques for acidic mucin?
What type of carcinomas can be diagnosed using staining techniques for acidic mucin?
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Which type of staining method would be ineffective for demonstrating the presence of calcium in tissues?
Which type of staining method would be ineffective for demonstrating the presence of calcium in tissues?
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Study Notes
Special Stains
- Routine stain is Hematoxylin and Eosin (H&E)
- Other stains are called "special stains" because they are used in specific situations for diagnostics.
Haematoxylin
- Haematoxylin is the oxidized form of hematein, a product from logwood trees.
- Nowadays, most hematein is synthetic because logwood trees are rare.
- Haematoxylin must be oxidized to be used as a stain. Oxidation can happen naturally via air or with chemicals like sodium iodate or mercuric oxide.
- It does not directly stain tissues, it needs a mordant.
- Mordants typically include metal cations like iron, aluminum, or tungsten.
- Different kinds of haematoxylin vary in intensity based on the chosen metal ion.
- Haematoxylin is a basic dye, and thus, has an affinity for nucleic acids in the cell nucleus.
- Haematoxylin stains can be either regressive or progressive.
Regressive Stain
- This stain method is also known as overstaining in some texts
- Slides are stained for a given amount of time, and then are treated with an acid-alcohol solution which removes some of the stain.
- It's good for large batches of slides to be stained, as slide staining consistency is more predictable.
Progressive Stain
- Slides are stained in haematoxylin until a desired level of intensity is reached.
Eosin
- Eosin is a common dye to stain the cytoplasm of cells in histology.
- Eosin is an acidic dye that binds to basic cell components. Those components are mainly proteins in the cell's cytoplasm.
- Eosin stains the cytoplasm a bright pink colour.
Special Stains (Tissue Needs)
- Mucin stains
- Glycogen stains
- Melanin stains
- Calcium stains
- Lipochrome (lipofuschin) pigments
- Iron (hemosiderin)
- Fat stains
- Connective tissue stains
Glycogen Demonstration Techniques
- Periodic acid-Schiff reaction (PAS)
- Best's carmine
- Hexamine silver technique
Periodic acid-Schiff reaction (PAS)
- Periodic acid selectively oxidizes glucose residues, creating aldehydes.
- Aldehydes react with Schiff reagent.
- Detects glycogen, glycoproteins, mucoproteins, basement membranes, mucin, and fungi.
- A predigestion step with amylase or diastase removes the staining for glycogen.
- Nuclei stain blue whilst collagen stains pink.
PAS Staining Uses
- Distinguishing different types of glycogen storage disease.
- Identifying certain types of cancer like bladder, kidney, liver, ovary (adenocarcinoma), pancreas, and lung (adenocarcinoma) cancers
Melanin Stains
- Melanin is commonly found in the skin, eyes, and substantia nigra of the brain and hair follicles.
- Pathological conditions may cause melanin to appear in benign tumors, nevus cell tumors, and malignant melanomas.
- Demonstration techniques include Masson-Fontana (commonly used), Schmorl's method, or an enzyme histochemical method called DOPA-oxidase, bleaching techniques, or formaldehyde-induced fluorescence.
Calcium Stains
- Abnormal calcium deposits can occur throughout the body.
- H&E staining results in deep blue-purple staining of calcium.
- Von Kossa method is used to detect calcium or calcium salts. In this method, tissues are treated with a silver nitrate solution. The silver then deposits themselves by replacing the calcium. Strong light makes the calcium appear as metallic silver (visualised as black deposits).
Lipochrome (Lipofuscin) Pigments
- Breakdown products from oxidized lipids and lipoproteins.
- Common wear and tear pigments in heart, liver, CNS, and adrenal cortex.
- Lipochromes can be stained by Sudan black B stain.
- They can also exhibit strong orange autofluorescence in formalin-fixed, unstained paraffin sections.
- Other staining methods include those developed by Schmorl and Long Ziehl-Neelsen.
Iron (Hemosiderin)
- Hemosiderin or storage iron granules can be present in areas of old hemorrhage or tissue deposits.
- Found in reticular endothelial organs (e.g., spleen, liver, bone marrow).
- Hemochromatosis is a condition of iron overload that is associated with organ failure.
- A classic method to visualise iron is Perl's Prussian blue reaction.
Fat Stains
- Oil Red O (ORO) stain can be used to identify neutral lipids and fatty acids in smears and tissue samples.
- ORO is quick and simple.
- Useful for spotting fat emboli in lung or clotting sections of peripheral blood.
- Fresh smears or cryostat sections are required because lipids can be removed in routine tissue processing, with fixatives, or from alcohol based clearings.
Connective Tissue Stains
- Trichrome stains highlight the collagenous stroma in various organs, helping to determine tissue injury patterns.
- Helps identify normal structures like connective tissue capsules in organs, the lamina propria of the gastrointestinal tract, bronchovascular structures in the lungs.
- Reticulin stains are useful in parenchymal organs (like the liver and spleen) to outline their architecture.
- Reticulin helps visualise delicate, argyrophilic reticular fibers.
- Reticulin staining can help highlight the growth pattern of neoplasms.
- Elastic tissue staining uses methods such as Verhoff's haematoxylin, Orcein methods, and Aldehyde fuchsin.
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Description
This quiz covers the essential concepts of special stains used in histological diagnostics, including haematoxylin and its properties. Learn about the staining techniques such as regressive staining and the role of mordants in enhancing visibility. Test your knowledge on the various classifications and applications of these stains.
