Term
| What are the basic steps in tissue preparation? |
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Definition
| fixation, embedding, clearing, sectioning, staining |
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Term
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Definition
| Carry negative charge, react with ionized amino acid groups of proteins. Main example is eosin |
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Term
| Where in the cell is acidophilia (eosinophilia) normally seen? |
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Definition
| cytoplasmic filaments, intracellular membranous components, unspecialized cytoplasm, and extracellular fibers |
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Term
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Definition
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Term
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Definition
| carry positive charge, react with phosphate groups of nucleotides, sulfate groups of glycosaminoglycans, and carboxyl group of proteins. Main example is hematoxylin, altho it technically isn't a basic dye |
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Term
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Definition
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Term
| Where in the cell is basophilia normally seen |
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Definition
| heterochromatin, nucleoli, |
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Term
| meaning of pale cytoplasm in H&E |
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Definition
| there is a lot of glycogen or lipid, |
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Term
| Meaning of intense cytoplasmic eosinophilia |
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Definition
| cell is not metabolically active |
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Term
| meaning of intense cytoplasmic basophilia |
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Definition
| cell is metabolically active/producing lots of protein (basophilia due to RNA in the cytoplasm) |
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Term
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Definition
| shift in color of basic dyes from blue to red or purple due to presence of polyanions |
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Term
| How are frozen sections used in clinical practice? |
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Definition
| To evaluate tissue during surgery when information is needed quickly |
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Term
| Explain Periodic Acid-Schiff (PAS) reaction |
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Definition
| stains carbohydrates and carbohydrate-rich macromolecules. It is used to demonstrate glycogen in cells, mucus in various cells and tissues, the basement membrane that underlies epithelia, and reticular fibers in connective tissue. It stains aldehyde groups red. |
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Term
cellular component stained by the Feulgen reactions, and how this
reaction is used in a clinical setting |
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Definition
| Feulgen reactions stain DNA. It is used in Feulgen microspectrophotometry in evaluating the metastatic potential of tumors. |
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Term
| Basic concept of enzyme digestion |
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Definition
| digestion of a section adjacent to one stained for a specific component, such as glycogen, DNA, or RNA, can be used to confirm the identity of the stained material via abolition of staining after enzymatic treatment |
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Term
| Basic concept of enzyme histochemistry |
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Definition
| identifies and localizes enzymes in cells and tissues by staining for the reaction product of the enzyme activity via a capture reagent |
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Term
| Basic concept of immunocytochemistry |
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Definition
| a specific protein, is isolated from one species (such as a rat), and injected into the circulation of another species (such as a rabbit). In the immunized rabbit, the rat protein molecules are recognized by the rabbit immune system as foreign antigens, causing polyclonal antibodies that act against the rat proteins. The antibodies are removed from the blood, purified, and conjugated with a fluorescent dye and can be used to locate the protein molecules in rat tissues or cells |
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Term
| basic concept of direct and indirect immunofluorescence |
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Definition
| fluorescent antibodies are used to locate antigen. In direct immunofluorescence, a fluorescent primary antibody binds directly to the antigen. In indirect immunofluorescence, a fluorescent secondary antibody binds to a primary antibody that is bound to the antigen |
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Term
| basic concept of autoradiography |
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Definition
| radioactivevly tagged precursors of a molecule are incorporated into cells and tissues before fixation and are then detected via a photographic emulsion placed over a tissue section. |
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Term
| how is immunocytochemistry used in clinical practice |
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Definition
| used to detect and diagnose tumor metastasis, differentiate subtypes of tumors and stages of their differentiation, and to identify microorganisms in blood and tissue fluids |
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Term
| Difference between magnification and resolution |
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Definition
| Magnification is when an image is made larger to allow visualization of greater detail. Resolution is the distance by which two objects must be separated so as to be seen as two objects |
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Term
| Describe phase contrast microscopy |
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Definition
| light passing through areas of relatively high refractive index (denser areas) is deflected and becomes out of phase with the rest of the beam of light that has passed through the specimen. The microscope adds other out-of-phase wavelengths to abolish the amplitude of the initially deflected portion of the beam, creating contrast in the image. |
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Term
| Describe dark-field, fluorescent, confocal and UV microscopy |
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Definition
| In dark-field microscopy, only light that has been scattered or diffracted by structures in the specimen reaches the objective. Fluorescent microscopy displays naturally occurring or induced fluorescent molecules. Confocal microscopes allow visualization of a biologic specimen in three dimensions by using a detector aperture (pinhole) that only allows “in-focus” light to pass into a detector. Ultraviolet (UV) microscopy depends on the absorption of UV light by molecules in the specimen |
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Term
| Describe polarizing microscopy |
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Definition
| a polarizing filter (polarizer) to a light microscope between the light source and the specimen and a second polarizer (analyzer) between the objective lens and the viewer. The difference between the angles of rotation of the polarizer and analyzer is used to determine the degree by which a structure affects the beam of polarized light |
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Term
| describe atomic force microscopy (AFM) |
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Definition
| an ultrasharp pointed probe scans the specimen following parallel lines along the x-axis, then along the y-axis. The sharp tip delfects a cantilever, which has a reflective upper surface. A laser beam is directed off the cantilever to a dode. As the tip moves up and down the z-axis as it traverses the specimen, the movements are recorded on the diode as movements of the reflected laser beam. |
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Term
| Basic setup of light microscope |
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Definition
| A light microscope contains a light source for illumination of the specimen, a condenser lens to focus the beam of light at the level of the specimen, a stage on which the slide or other specimen is placed, an objective lens to gather the light that has passed through the specimen, and an ocular lens through which the image formed by the objective lens may be examined directly. It has an approximate resolution of 0.2 um. |
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Term
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Definition
| A transmission electron microscope uses an electron source (cathode or electron gun) to emit electrons. The electrons are attracted toward an anode. An electrical difference beween the cathode cover and the anode imparts an accelerating voltage to the electrons, creating the electron bream. The beam then passes through a series of electromagnetic lenses that serve the same function as the glass lenses of a light microscope. TEM has a theoretical resolution of 0.05 nm and a resolution in tissue section of 1.0 nm. |
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