Term
| Three Basic Steps of Tissue Preparation |
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Definition
| Filtration, Infiltration, Staining |
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Term
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Definition
| Chemical process used to preserve from decay by terminating any ongoing biological reactions. |
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Term
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Definition
37% AQUEOUS SOLUTION FORMALDEHYDE USED FOR FIXATION
IT CROSS-LINKS THE AMINO GROUPS, FIXING THEM IN THEIR POSITION. IT DOESN'T ALTER THEIR 3D |
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Term
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Definition
| WATER IS USED TO REMOVE THE FORMALIN. THEN DEHYDRATED WITH GRADED ALCOHOLS. THEN THE TISSUE IS PLACED IN XYLENE, WHICH WILL INFILTRATE INTO THE TISSUES TO REMOVE THE ALCOHOL. PARAFFIN, AN EMBEDDING MEDIUM, IS PUT INTO TISSUE TO MAKE IT HARD AND REPLACE THE XYLENE. THE HARD TISSUE IS THEN CUT WITH A MICROTOME, DRIED AND EXAMINED UNDER A MICROSCOPE. |
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Term
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Definition
| Hematoxylin and Eosin are most commonly used to stain. Then the tissue is mounted by placing a plastic mounting material over the sections. Then a final slip is placed on top. |
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Term
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Definition
imparts a blue color
Stains DNA and CYTOPLASMIC RNA |
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Term
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Definition
Imparts a red color
Stains cytoplasms and extracellular fibers |
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Term
| How do you retain lipids when preparing tissue? |
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Definition
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Term
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Definition
Embedding media used to improve resolution and/or accommodate special stains...i.e. - those not compatible with Paraffin
Allows much thinner sections and great for electron microscopy |
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Term
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Definition
Used to infiltrate phospholipids, which will improve membrane preservation
Not necessarily a stain but allows better visualization of phospholipids with light microscope
Allows view of specimen with the electron, rather than light, microscope |
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Term
| 3 things that determine the choice of procedure for tissue preparation |
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Definition
1. Specific binding of a dye
2. USe of Fluorescent dye-labeled antibody
3. Enzyme activity |
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Term
| Periodic Acid- Schiff Reaction |
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Definition
Stains carbohydrates
Stains a MAGENTA color
Useful for staining GLYCOGEN, MUCUS, BASEMENT MEMBRANE, and RETICULAR FIBERS |
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Term
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Definition
Useful for staining DNA (NOT RNA) in a stoichiometric manner
Produces an ACID HYDROLYSIS with cleaves PURINES from the deoxyribose of DNA
Produces a MAGENTA color |
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Term
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Definition
most commonly used fluorochrome
absorbs light at one wavelength and emits visible light at a different wavelength
absorbs UV light and emits GREEN LIGHT |
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Term
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Definition
Antibodies are labeled with a fluorochrome
Fluorescently labeled antibody binds to it's specific antigen in fixed or frozen tissue
Emitted light from the fluorochrome locates the antigen |
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Term
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Definition
Locates an enzyme in tissues by its reaction product
A capture agent that can be visualized with a microscope binds to the product, locating the enzyme
LEAD IONS are used as a capture agent for phosphatases, forming lead phosphate, a visible precipitate |
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Term
| How are lead ions used in enzymatic histochemistry? |
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Definition
| LEAD IONS are used as a capture agent for phosphatases, forming lead phosphate, a visible precipitate |
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Term
| Most commonly used light microscope |
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Definition
| Bright Field REquires fixation and staining |
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Term
| Types of Light Microscopes |
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Definition
Bright Field
Phase Contrast
Polarizing Microscope
Confocal Microscope |
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Term
| Phase Contrast Light Microscope |
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Definition
Depends of differences in refractive index of the cellular components (denser areas appear as darker images)
Enhances contrast WITHOUT staining, which allows the study of LIVING CELLS and TISSUES |
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Term
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Definition
| Useful to locate structures with a highly ordered, repeating molecules, such as COLLAGEN and ACTIN |
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Term
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Definition
| Utilizes lasers and reconstruction computer software to form a 3D, layer-by-layer- image that can be rotated and viewed from any orientation |
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Term
| Types of Electron Microscopes |
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Definition
| Transmission (TEM) and Scanning (SEM) Electron Microscopes |
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Term
| Trasmission Electron Microscope |
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Definition
Beam of electrons transmitted THROUGH ultra thin sections of tissue
Provides a wavelength of 1/2,000 of a light beam
Results in resolution 1000X better than the light microscope
Electron beam is focused by electromagnets
appears as shades of grey on a PHOSPHOR-COATED screen
tissues embedded with METHYLMETHACRYLATE |
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Term
| With TEM, what is used as an alternative to formalin, Hematoxylin, and Eosin (used in light microscopy)? |
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Definition
| Glutaraldehyde, Osmium Tetroxide, and Uranyl Acetate |
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Term
| With TEM, what is used as an alternative to Hematoxylin and Eosin when staining? |
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Definition
| Osmium Tetroxide and Uranyl Acetate |
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Term
| Which type of microscopy uses copper grids, as opposed to glass slide? |
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Definition
| Transmission Electron Microscopy |
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Term
| Scanning Electron Microscope |
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Definition
an electron beam scans the SURFACE of a specimen
after fixation and dehydration, samples are coated with gold-carbon film
reflected electrons are collected and processed to form a 3# image on a cathode ray tube |
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Term
| With SEM, after fixation and dehydration, what are samples coated with? |
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Definition
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Term
| How is the image processed with scanning electron microscopes? |
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Definition
| reflected electrons are collected and processed to form a 3D image on a CATHODE RAY TUBE |
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Term
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Definition
allows surface topography at MOLECULAR and ATOMIC RESOLUTION
laser sensor either touches or taps the surface of the tissue
data points from the X,Y, and Z axes are converted in to a 3D image
doesn't require a vacuum (unlike TEM and SEM), which allows imaging of living tissues |
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Term
| Which type of microscope is useful to image the surface topography at molecular and atomic resolution? |
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Definition
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Term
| Does TEM require a vacuum to function? |
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Definition
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Term
| Does SEM require a vacuum to function? |
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Definition
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Term
| Do atomic force microscopes require a vacuum to function? |
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Definition
| No, therefore it can allow the visualization of living tissues |
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Term
| Which microscopes allow the visualization of living tissue? |
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Definition
Atomic Force Microscope (does not require a vacuum to function)
Phase Contrast (enhances contrast of tissue without staining) |
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Term
| How is the electron beam focused in TEM? |
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Definition
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Term
| What type of staining would be used to identify tissues of the digestive tract, salivary glands, mucus, and the basement membrane, reticular fibers, and collagen? |
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Definition
| Periodic Acid Schiff (stains carbohydrates) |
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