Chapter 11: Pigments, Minerals, and Cytoplasmic Granules Flashcards
Endogenous Pigment
A pigment formed within the body
Exogenous Pigment
A pigment formed externally which is then taken into the body
Carbon: black, often in lung and associated lymph nodes
Asbestos fibers: birefringent in lungs
Tattoo ink: skin and associated lymph nodes
Metals
Hematogenous Pigment
Pigments derived from the blood
Hemoglobin, Iron, Hemosiderin, Biliverdin (bile)
Anthracotic Pigment
black discoloration of bronchi from carbon pigment, usually due to smoke or coal inhalation
Endogenous, Nonhematogenous Pigment
Not derived from blood
Lipidic (lipofucsin and ceroid) and non-lipidic pigments (melanin)
Mineral
Metallic and non-metallic ions necessary for growth and other bodily functions
Calcium, ferric/cupric phosphate/carbonate
Silver, lead, copper, gold
Artifact
Deposited on tissue as a result of chemical action
Usually occur during processing due to certain fixatives
Mercury, Chrome, Formalin, Malarial
Hemoglobin
Protein in red blood cells for transporting oxygen
Stains with acid dyes such as eosin
May be pathologically found in recent hemorrhages or renal tubules after hemolysis
Hemosiderin
Storage form of iron in bone marrow and spleen, recycled for production of hemoglobin
Yellow to brown pigment
Large deposits are typically pathological since a majority of the iron is in use as RBCs
Bile (biliverdin)
Greenish bile pigment, component of Heme in RBCs
Reduced to bilirubin in the liver and is secreted as a component of bile
Demonstrated by oxidizing bilirubin (yellow-brown) to biliverdin (green)
Abnormal accumulations can result in jaundice (yellowing of the skin), and deposition in the Kupffer cells and hepatocytes
Hematoidin
Formed in tissues as a result of hemorrhage and reduced oxygen tension
A pigment similar to bilirubin that is also oxidized to biliverdin by bile-demonstrating techniques
Lifespan and degradation of erythrocytes
Lifespan of 120 days
Then split open by hemolysis or phagocytosed by macrophages in the spleen
Break down into Heme and Globin
Heme breaks down into iron and biliverdin (greenish bile pigment)
Function of Iron, where is it found?
Component of Red blood cells, also found in liver and bone marrow as hemosiderin
Hemachromatosis
Disease caused by excessive absorption of dietary iron characterized by excessive hemosiderin deposits
Can be differentiated from other yellow-brown pigments by the Prussian-Blue reaction
Bilirubin function and characteristics
(Yellow-brown) Reduced form of biliverdin (green bile pigment )
Melanocytes
Cells responsible for demonstration of melanin, contain dopa oxidase
Demonstrated by exposure of frozen sections to a buffered solution of dopa, melanin, or melanin-like pigment
Melanin
Derived from tyrosine and is characteristically a brown-black pigment
Summary of melanin production
tyrosine is oxidized to dopa which is oxidized to melanin
What is lipofucsin, where is it found?
A lipidic pigment indicating “wear and tear” which collects in more permanent tissues such as the heart, liver, and neurons
Yellow-brown and stains with Oil Red O, Sudan Black B, and PAS
What is ceroid, where is it found?
A lipid pigment seen in hepatocytes and macrophages with liver cirrhosis
Yellow-brown, stains with Oil Red O, Sudan Black B, and PAS.
Can be differentiated from lipofucsin using acid fast stain (ceroid is acid-fast positive)
Where are three places melanin is found in the body?
eyes, hair, skin
Method for bleaching melanin pigment
Expose to an oxidizing agent, such as 10% hydrogen peroxide or 0.25% potassium permanganate followed by oxalic acid (to clear sections of color)
This is to help retain cell detail when melanin pigment is present in large quantities
Preferred fixative for minerals
Formalin because metallic fixatives (mercury, chrome) would leave artifacts in the tissue
What are urate crystals, where are they found?
Urate crystals (sodium/uric acid deposits) are found in tissue and joints of people suffering from gout They are an endogenous deposit, originating inside the body They must be fixed in methanol (non-aqueous) because they are water soluble; are birefringent (polarizing microscopy), and can be demonstrated with argentaffin methenamine silver techniques
Argentaffin vs Argyrophilic silver reactions
Argyrophilic cells can be impregnated with silver, but require an external reducer (chemical or light) to demonstrate metallic silver. Can only be demonstrated with Argyrophil techniques.
Argentaffin cells can be impregnated with silver and reduce those ions to their visible metallic form. Can be demonstrated wit both argentaffin and argyrophil techniques
Silver stains are used to demonstrate cytoplasmic granules
Prussian Blue Purpose
Detection of ferric iron in tissues
Typically found in small amounts in the bone marrow and spleen
Excess hemosiderin (idiopathic hemochromatosis can lead to organ failure and death
Prussian Blue Principle
Detects the ferric iron (Fe3+) in loosely bound protein complexes (such as hemosiderin)
Strongly bound iron in hemoglobin will not react with Prussian Blue
Iron ions in the tissue react with acidic potassium ferrocyanide to form Prussian-Blue
Prussian Blue Preferred Fixative
Alcohol or 10% NBF
Prussian Blue Basic Procedure
- Deparaffinize, hydrate (use non-metallic forceps)
- Place slides in potassium-ferrocyanide and hydrochloric acid solution for 20 minutes
- Wash in distilled water
- Counterstain in nuclear fast red
- Rinse thoroughly in tap water to prevent cloudiness
- Dehydrate, clear, coverslip
Prussian Blue Results
Nuclei and hemofuchsin: bright red
Hemosiderin (iron): blue
Background: pink
Prussian Blue Technical Notes
Staining containers must be clean or residual iron will cause diffuse background staining
Acid decalcifiers for bone can dissolve iron; use 3% or 5% acetic acid or formic acid to preserve iron
Excess nuclear fast red must be thoroughly washed out to prevent cloudiness when placed in alcohol dehydrant
Turnbull Blue Purpose
Detection of Ferrous iron Fe2+ (very toxic) in tissue, rapidly converted to ferric form
Turnbull Blue Principle
Ferrous iron in the tissue reacts with acidic potassium-ferricyanide to form Turnbull blue
Turnbull Blue Preferred Fixative
alcohol or 10% NBF
Turnbull Blue Basic Procedure
- Deparaffinize, hydrate (use non-metallic forceps)
- Place slides in freshly prepared ferricyanide staining solution
- Wash in acetic acid
- Counterstain in nuclear fast red
- Rinse thoroughly in distilled water to prevent cloudiness
- Dehydrate, clear, coverslip
Turnbull Blue Results
Ferrous iron: blue
Background: pink-red
Turnbull Blue Technical Notes
Staining containers must be clean or residual iron will cause diffuse background staining
Acid decalcifiers for bone can dissolve iron; use 3% or 5% acetic acid or formic acid to preserve iron
Excess nuclear fast red must be thoroughly washed out to prevent cloudiness when placed in alcohol dehydrant
Schmorl Technique Purpose
Demonstrates reducing substances present in tissue including melanin, argentaffin granules, and formalin pigment
Schmorl Technique Principle
Ferric iron Fe3+ in the staining solution reacts with reducing substances in teh tissue to become ferrous iron Fe2+. The ferrous ions Fe2+ combine with ferricyanide to form insoluble Turnbull blue (ferrous ferricyanide)
Schmorl Technique Preferred Fixative
10% NBF
Schmorl Technique Basic Procedure
- Deparaffinize, hydrate
- Place in ferric chloride-potassium ferricyanide
- Rinse in distilled water
- Stain in Mayer mucicarmine
- Rinse in distilled water
- Counterstain in Metanil yellow
- Rinse in distilled water
- Dehydrate, clear, coverslip
Schmorl Technique Results
Reducing substances: blue-green
Goblet cells, mucin: rose
Background: yellow-green
Schmorl Technique Technical Notes
Works well on GI tract because of mucin demonstration, nuclear fast red is an acceptable alternative to Mayer mucicarmine
Glassware must be clean and solutions must be fresh to avoid non-specific iron background staining
Fontana Masson Purpose
Demonstrate argentaffin substances such as: melanin, argentaffin granules of carcinoid tumors, and some neurosecretory granules
Fontana Masson Principle
Some tissue components are argentaffin and can bind metallic silver without the need of an external reducer
Fontana Masson Preferred Fixative
10% NBF
Skin as melanin control, small appendix as argentaffin granule control
Fontana Masson Basic Procedure
- Deparaffinize, hydrate
- Immerse slides in silver nitrate solution. The reaction should b stopped when granules are dark brown and the background is colorless.
- Rinse in distilled water
- Immerse in gold chloride (toner)
- Rinse in distilled water
- Place in sodium thiosulfate (remove excess unreduced silver)
- Rinse in distilled water
- Counterstain in nuclear fast red
- (wash thoroughly in running water to prevent cloudiness)
- Dehydrate, clear, coverslip
Fontana Masson Results
Melanin: black
Argentaffin granules: black
Nuclei: pink
Fontana Masson Technical Notes
This technique is not specific for melanin and argentaffin granules. Other reducing substances, such as formalin will also give a positive reaction
Overstaining will result in a dirty grey background and loss of contrast
Silver solutions should be discarded on the day of use because they can form explosive compounds after standing for several days
For melanin, duplicate sections should be treated with the melanin bleach procedure. if the pigment is melanin it will disappear with this treatment
Grimelius Purpose
Demonstrate argyrophil granules in neurosecretory tumors
Grimelius Principle
Tissue binds silver ions, but requires an external reducer to reduce silver to its visible metallic form
Grimelius Preferred Fixative
10% NBF
Grimelius Basic Procedure
- Deparaffinize, hydrate
- Place in working silver solution
- Drain slides
- Place in reducing solution (hydroquinone)
- Rinse in distilled water
- Repeat step 2
- Drain and place slides in reducing solution again
- Rinse in distilled water
- Counterstain with nuclear fast red
- Rinse thoroughly in distilled water to prevent cloudiness
- Dehydrate, clear, coverslip
Grimelius Results
Argentaffin granules: dark brown to black
Argyrophil granules: dark brown to black
Nuclei: red
Background: pale yellow brown
Grimelius Technical Notes
Argentaffin substances will also stain with this method because they will bind and reduce the silver on their own. To differentiate between argentaffin and argyrophil both Grimelius and Fontana Masson techniques must be performed and compared
Churukian-Schenk Purpose
Demonstrate argyrophil granules in neurosecretory tumors
Churukian-Schenk Principle
Argyrophil stains/substances require an external reducer to demonstrate visible metallic silver
Churukian-Schenk Preferred Fixative
10% NBF
argyrophil-positive carcinoid tumor, or section of small intestine (containing argentaffin granules)
Churukian-Schenk Basic Procedure
- Deparaffinize, hydrate to acidified water, pH 4.0-4.2
- Place slides in silver-nitrate
- Rinse in distilled water
- Transfer to reducing solution (hydroquinone)
- Rinse in distilled water
- Return slides to the same silver stain
- Rinse in distilled water
- Place in reducing solution
- Rinse in distilled water
- Counterstain in nuclear fast red
- Rinse thoroughly in distilled water to prevent cloudiness
- Dehydrate, clear, coverslip
Churukian-Schenk Results
Argyrophil granules: black
Argentaffin substances: black
Nuclei: red
Background: yellow-brown
Churukian-Schenk Technical Notes
Shelf-life of silver-nitrate and hydroquinone can be greatly increased by storing these chemicals at 4C
Gomori Methenamine Silver Purpose
Demonstrate urates in tissue
Gout is the deposition of urate crystals, especially around joints and in soft tissues
Gomori Methenamine Silver Principle
Urates are stained black by reacting with silver (argentaffin/ no external reducer)
Gomori Methenamine Silver Preferred Fixative
absolute alcohol must be used because urates are water soluble
Gomori Methenamine Silver Basic Procedure
- Deparaffinize and rinse with absolute alcohol. DO NOT HYDRATE (urate is water soluble)
- Place sections in working methenamine silver solution that has been preheated to 60C
- Incubate for 30 minutes. Urate crystals should be black
- Rinse in distilled water
- Place sections in sodium thiosulfate (removes unreduced silver)
- Wash in running water GENTLY to prevent tissue from washing off
- Rinse in distilled water
- Counterstain with light green
- Dehydrate, clear, coverslip
Gomori Methenamine Silver Results
Urates: black, also birefringent
background: blue-green
Hall Purpose
Demonstrate presence of bilirubin and distinguish bile pigment from other pigments
Hall Principle
Easily identifiable green color develops when bilirubin is oxidized to biliverdin in an acid medium
ferric chloride in trichloroacetic acid facilitates the oxidation (fouchet reagent)
Hall Preferred Fixative
10% NBF
Hall Basic Procedure
- Deparaffinize, hydrate
- Wash in distilled water
- Stain in Fouchet reagent (trichloroacetic acid and ferric chloride)
- Wash in tap water, rinse in distilled water
- Stain in van Gieson
- Place in 95% alcohol and rinse well
- Dehydrate, clear, coverslip
Hall Results
Bile or bilirubin: emerald green to olive drab
Background: yellow
Von Kossa Purpose
Identify the presence of calcium
Von Kossa Principle
Silver reacts with carbonate and phosphate anions of the calcium salts, not calcium directly.
Bright light reduces the silver salt to metallic silver and unreduced silver is removed by sodium thiosulfate (argyrophil)
Von Kossa Preferred Fixative
Alcohol or 10% NBF
Avoid acidic fixatives because they break down calcium deposits into ions
Von Kossa Basic Procedure
- Deparaffinize, hydrate
- Place in silver nitrate, and expose to bright sunlight. Stop the reaction when the calcium salts are brown-black
- Rinse in distilled water
- Place in sodium thiosulfate
- Wash in distilled water
- Counterstain in nuclear fast red
- Wash thoroughly in water to prevent cloudiness
- Dehydrate, clear, coverslip
Von Kossa Results
Calcium salts: black
Background: red
Von Kossa Technical Notes
Alcoholic iodine for removing mercury may also remove calcium salts
Unbuffered formalin may reduce silver
Artificial light produces a brown rather than black pigment
Alizarin Red S Purpose
Identify the presence of calcium
Alizarin Red S Principle
Alizarin Red S will actually react with all of the following cations: Calcium ,magnesium, manganese, barium, and strontium.
However, only Calcium is typically present in large enough quantities ot be demonstrated
Alizarin Red S Preferred Fixative
Alcoholic formalin or 10% NBF
Alizarin Red S Basic Procedure
- Deparaffinize and hydrate to 50% alcohol
- Rinse in distilled water
- Place slides in Alizarin Red S, remove slides when an orange-red lake forms
- Shake off excess dye and blot
- Dehydrate in acetone and in acetone-xylene
- Clear and coverslip
Alizarin Red S Results
Calcium deposits: orange-red (also birefringent)
Rhodanine Copper Purpose
Detection of copper in tissue, especially when looking for Wilson disease in the liver
Rhodanine Copper Principle
Demonstrates the protein that copper bonds to rather than the copper itself, so there is a chance for false positives
Rhodanine Copper Preferred Fixative
10% NBF
Control must contain copper and be cut at -10uM
Rhodanine Copper Basic Procedure
- Deparaffinize, hydrate
- Place slides in Rhodanine solution for 18 hours at 37C
- Rinse in distilled water
- Stain in Mayer hematoxylin
- Rinse with distilled water
- Rinse in sodium borate
- Rinse in distilled water
- Dehydrate, clear, coverslip
Rhodanine Copper Results
Copper: bright red to red-yellow
Nuclei: light blue
Rhodanine Copper Technical Notes
If the concentration of copper is too low, fading may occur and make it difficult to distinguish between copper and lipofucsin
Fetal liver is a good control for copper
Do not overstain with hematoxylin or the copper may be masked
How to remove Chrome pigment
Wash tissue in running water before dehydration
How to remove Mercury pigment
Iodine, then sodium thiosulfate
How to remove Formalin pigment
Absolute alcohol saturated with picric acid, or 70% alcohol containing ammonium hydroxide
Melanin Bleaching Procedure
- Deparaffinize, hydrate
- Treat with potassium permanganate
- Wash well in tap water
- Place slides in oxalic acid
- Wash in running tap water
- Rinse in distilled water
- Stain in nuclear fast red
- Rinse thoroughly with water to prevent cloudiness
- Dehydrate, clear, coverslip