Intro to Histo- Electron Microscope Flashcards
What are 7 types of Dyes for Electron Microscope?
- Sudan Stains
- Osmium Tetroxide Stain
- Periodic Acid Schiff (PAS) stain
- Alcian blue stain
- Trichrome Stain
- Van Gieson Stain
- Giemsa stain
What are 2 types of Metal impregnation techniques?
- Silver Stain
- Reticular fibers (Silver salts)
- Type 2 Collagen
- Golgi’s method
* For Nervous tissue
What are 3 main Heavy Metal Ion Stain?
- Lead citrate
- Uranyl acetate
- Osmium tetroxide
What is Oil red O Stain?
- Sudan IV stain similiar to Oil Red O stain
- Used to detect Fat Emboli in Lungs (after a fracture of the lower leg)
* Identifies tumors, lipomas, and liposarcomas - Stains
- Lipids: RED
- Nuclei: BLUE/BLACK
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What is Sudan Black Stain?
- Stains
* Lipids: BLACK
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What is Osmium Tetroxide Stain?
- Stains
- Lipids: BLACKish-Brown
- Myelin: Black
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What is Periodic acid-Schiff (PAS)?
- Used for Carbohydrates macromolecules (polysaccrides)
- Stains
* Magenta - Carbohydrates
- Glycogen- Muscle cells (Hepatocytes)
- Glycoprotein (thyroid tissue)
- Ex: Mucin
- Glycocalyx
- Basal lamina
- Lysosomal enzymes (phagocytosis)
- Ex: Mucin
- Proteoglycan (CT and ECM)
- Form gels
- Lubricates joints
- Holds cells and tissue
- Flexiblity of cartilage
- Form gels
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What is Alcian blue?
- Stains
* Acid Mucin: BLUE - Does not stain neutral mucin (alkaline)
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What does Alcian blue/ PAS combination stain?
- Stains
* Apical neutral/acid mucin droplets of intestinal goblet: BLUE-PURPLE
How does PAS staining help with diagnosing?
- Glycogen storage disease
- Adenocarcinomas and Cystic Fibrosis
* Increased mucin production - Paget disease
* Of the breast and nipple - Whipple’s disease
- Infectious disease that first affect GI tract and causes malabsorption
- PAS stains: MACROPHAGES
- Mycosis fungoides
* Aggregates of PAS positive lymphocytes in epidermis - Erythroleukemia
- A leukemia of immature red blood cells
- Stain: Bright Fuchsia (Purple-red)
What are 3 main CT stains?
- Trichrome stain
- Elastic fiber stain
* Van Gieson - Reticular fiber stain
* Silver salt/stain
What is Trichrome Stain?
- Stains Collagen
- Useful for Liver Cirrhosis
* Produces large amounts of collagen/scar tissue
What is Mallory Trichrome Stain?
- Used on CT
* Visualize collagen and reticular fibers - Stains
- Collagen and Reticular fibers: BLUE
- Smooth muscle and Nuclei: RED
- Elastic fibers: PINK
- Red Blood Cells: ORANGE
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What is Masson’s Trichrome?
- Helpful for differentiating Cellular from Extracellular Items
- Stains
- Collagen fibers: GREEN
- Smooth Muscle: RED
- Cytoplasm: PINK to RED
- Nuclei: BLACK
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What is Elastic Fiber Stain? (Van Gieson)
- Differentiate between Collagen and Smooth Muscle
* Tumors - Stains:
- Elastic Fibers: Black/Purple-black
- Collagen: RED
- Cytoplasm, muscle, RBC: YELLOW
- Nuclei: BLACK/BLUE-BLACK
- Cartilage: PINK
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What are 2 types of Metal Impregnation Technique?
- Reticular Fiber Stains
* Silver salts - Golgi Silver Impregnation Technique
What are Reticular fibers stain in Metal Impregnation technique?
- Stains
* Reticular Fibers: BLACK - Reticular fibers (reticulin)
- Look like Fine Black Threads
- Form networks
- Support cellular components of Liver and Lymphoid organs
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What is the Golgi’s method?
- Most common for Nervous Tissue
- Stains
* Neurons, Glia, and Vascular System: BLACK on a YELLOW/ORANGE background
*Image shows Pyramidal and Purkinje Cells
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What is Giemsa Stain?
- Used for BLOOD CELLS and SMEAR CELLS
* Bone Marrow - Stains:
- Nuclei: BLUE to VIOLET and background pale BLUE
- Erythrocytes: PALE PINK
- Platelets and Leukocytes: BLUE
- Diagnosis for:
- Malaria
- Babesiosis
- Sleeping Sickness
- Schistosomiasis
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What is Heavy Metal Ion Stain?
- Used
- Transmission Electron Microscopy
- Subcellular structures
- Stain
* Tissue: BLACK
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What is the steps of Tissue Preparation for TEM?
- Size of sample
* 1 mm3 - Routine Fixants
- Glutaraldehyde
- Perserve Protein constituent by cross-linking
- Osmium Tetroxide
- Perserve membrane lipids (phospholipids)
- Embedding
* Epoxy Resin (Light microscope uses Wax) - Sectioning
- 40-90 nm
- Uses ultramicrotome either glass or diamond knife
- Mounting
* On Wire Mesh (grid)
What is Tissue Preparation for SEM?
- Same except after dehydration, spray coated with thin layer of heavy metal (usually gold)
- Staining
- Uranyl acetate: membrane structures and structures with nucleic acid
- Lead Citrate: Binds to RNA-containing structures
What is Transmission Electron Microscope (TEM)?
- Electrons transmitted through Specimen
- Resolution: 3 nm
- Observe: Organelles and ECM
- Imaging
- Bright, white areas
- Electron Lucent
- Black, dark areas
- Electron dense
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What is Scanning Electron Microscope (SEM)?
- Focused electron beam
* DOES NOT PASS THROUGH SPECIMEN - Image
* Scans only show the surface view
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What is an Artifact?
- Distortion of the tissue
- Ruins results
- Shrinkage, wrinkles, spaces, precipitates from the stain
What is Autoradiography?
- X-ray to localize newly synthesized macromolecules
- Specimen itself is the source of the radiation
What is Classical X-rays?
- Specimen placed between source of radiation and the film
- Absorption and scattering of radiation
What is Fibroblastic cells?
- Bipolar/Multipolor
- Elongated shape
- Grow attached to a substrate
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What is Epithelial-like cells?
- Polygonal
- Grow attached to substrate in discrete patches
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What is Lymphoblast-like cells?
- Spherical
- Grown in suspension without attaching to a surface
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What is Peroxidase?
- Promotes oxidation of substrates
* Transfer of hydrogen ion to hydrogen peroxide
What is Phosphatase?
- Removal of phosphate group from macromolecules
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- Kidney tubule treated histochemically
* Demonstrates Alkaline phosphastase
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- TEM image of Kidney cell
* Acid phosphatase - Dark areas
* Lead phosphate