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55 Cards in this Set
- Front
- Back
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What is the tokuyasu’s method?
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•Cryoprotection, antigen detection on cryosection-impregnation of secrose
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What enzymes are used in enzyme enzyme histochemistry?
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•Horseradish peroxidase
•Alkaline phosphatase •Bacterial beta-galactosidase |
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What are the metal salts we use in electron microscopy?
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•Uracyl acetate
•Lead citrate |
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What methods are used for EM of plasma membrane with E and P face (image)
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•SEM
•Cryofracture |
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Atomic force microscopy
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•Tapping mode is preferred
•It can scan surfaces |
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Process of preparation of electron microscopy
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•Sampling, Fixation, Embedding, Dehydration, Sectioning, Mounting, Contrasting, Observing
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When is enzyme histochemistry performed?
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•Prior to embedding
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What is the minimum thickness of an ultrathin slice?
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•60nm
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How many steps in enzyme histochemistry?
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Two steps: •1. A product is formed after the enzyme reacts with the substrate and 2. The reaction product is visualized by adding chromogen (substance which reacts in the tissue to create a coloured compound.
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What is hybridization used for?
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•Sequence of mRNA transcript
•The sequence of the genes |
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Freeze etching-How is it done? What do you observe? (not sure the exact question is)
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•Sublimation of ice under reduced pressure, lets you observe cell membranes •Sample must be shadowed |
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Sample preparation technique after fixation and dehydration
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•Critical point drying with CO2
•Mounting •Shading/spraying |
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What can be seen in negative contrast?
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•Viruses
•Bacteria •Macromolecules •DNA •Organelles |
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Definition of immunohistochemistry
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•specific binding of polyclonal antibodies to an epitope of the corresponding antigen on cryostat and paraffin sections of resin
•specific binding of monoclonal antibody to an epitope of the corresponding antigen or paraffin or cryostat sections of resin |
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How is SEM shaded?
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•Gold (Heavy metals-gold,palladium,platinum)
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What is a lectin?
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•a glycoprotein that can bind to a carbohydrate •protein able to bind to sugar in an oligosaccharide
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What occurs after reducing temperature in a cryostat?(don’t get this -_-)
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•Expansion of CO2 •Heating •Special type of freezing |
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How do we observe neutral lipids?
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•cryosection
•oil red o staining |
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In electron immunohistochemistry, when are antibodies added to antigens?
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•Before embedding
•Post embedding •Cryosections using Tokoyasu’s method |
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What moves the sensor in contact mode of AFM?
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•Repulsive forces (electrostatic repulsion) •Flexibility of the beam
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What is used to project the image in TEM?
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•CCD camera
•luminescent screen – fluorescent •conventional photography |
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In-situ zymography
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•Can be used to detect proteases •Substrate is consumed in-situ |
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How can we specimens be visualized in conventional histochemistry in an EM?
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•Reduced metal salts
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Instruments in in-situ hybridization
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•Needs a probe with complementary bases, nucleotides
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Types of elastic dyes
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•Orcein
•Resorcein fuchsine •Aldehyde fuchsine |
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Types of resin
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•Epoxy
•Acrylic •Polyester |
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Where can Tokoyasu’s method be used?
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•Ultrastructural immunohistochemistry
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What comes after fixation in SEM?
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•Dehydration->Critical point drying->mounting->spraying
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Slide of stained goblet cell
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• Possible stain: Mucicarmine, alcian blue or PAS •Special staining
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After fixation...:
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•Cut, washing, alcohol steps, clearing, embedding, sectioning, mounting
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Conventional microscopy
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•100(s)nm (hundreds of nm- it was written like this)
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Visualization in in situ-zymography (not sure)
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•Flurochrome
•Photography |
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What do you use looking for a specific sugar in an oligosaccharide chain
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•specific lectin
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What do you use looking for sugars of unknown oligosaccharide chain
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•panel of lectins
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Conventional histochemistry can be used to detect
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•elements
•DNA •lipids •saccharides •heamotogenic pigments •amino acids |
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What is conventional histochemistry
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•a chemical reaction tales place on the tissue (in situ) to give an originally uncoloured sample a colour
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Immunohistochemistry labels used in electron microscopy
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•Colloid gold
•Horseradish peroxidase |
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Immunohistochemistry labels used in light miscroscopy
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•flurochrome
•coloured reaction |
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Steps in tissue prep. SEM after dehydration
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•Fixing on a holder •Shading (Sputter coating-heavy metal) •Critical point drying |
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Contact mode in AFM, what does it use?
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•Repulsive forces (electrostatic forces) •Cantilever birefringement
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If you need want to see more details in the slide
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•change magnification to a higher one
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What can you do with a preparate after freezing
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•all options correct
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SEM is used for
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•observing the surface of cells
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SEM is used for
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•surface of biological and inorganic organisms
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TEM is used for
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•ultrastructure of macromolecules
• observing interior of cells or organelles |
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Cryostat-
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•co2 expansion, •electro thermal cell, •compressor freezer |
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What color ultrathin section can you use
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•grey
•white •gold |
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When does contrasting take place
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•fixation •dehydration •sectioning •(at the end) |
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What is heidenhein stain used for
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•myofibrils •mitochondria |
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What do you need for enzyme histochemistry
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•activity of enzyme
•stability of reaction products + coloured compound •structure of tissue •in natural environment |
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Size of visible things in light microscope
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•0.2 micrometers •200 nm |
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What stains with PAS
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•glycoproteins •saccharides |
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Order of steps?
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•trimming •Washing •sectioning |
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Synoptic stains
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•stains everything •no specific details |
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What is the method after tokujasu’’’
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•antigen is revealed
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