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41 Cards in this Set
- Front
- Back
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Objective Lens |
collects light from the specimen |
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Ocular Lens |
forms an enlarged virtual image |
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Resolution |
the ability to see two nearby points as distinct images |
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Feulgen Stain |
Specific for DNA, showing the chromosomes of an onion root tip cell in metaphase of mitosis at the time that it was fixed |
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Phase-contrast microscope |
makes highly transparent objects more visible by converting differences in the refractive index of some parts of the specimen into differences in light intensity |
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Whole mount |
Intact object, living or dead |
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Limit of Resolution |
depends on wavelength of light |
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Differential Interference Contrast (DIC) |
gives a three-dimensional quality to the image |
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Fluorescence Microscopy |
Green Jellyfish Protein (GFP) recombined with genes of interest in model organisms |
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Fluorescence Resonance Energy Transfer (FRET) |
A technique to measure changes in distance between two parts of a protein (or between two separate proteins within a larger structure). Based on the transfer of energy from a donor fluorochrome to an acceptor fluorochrome, changing the fluorescence intensity of the two molecules. |
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Video Microscopy |
Used to observe living cells; clarity increased |
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Laser Scanning Confocal Microscope |
produces an image of a thin plane located within a much thicker specimen; a laser beam is used to examine planes at different depths in a specimen |
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Transmission Electron Microscope (TEM) |
Use electrons instead of light to form images; 100-200x increase in resolution; limit of resolution is 10-15A; tissues stained with heavy metal for contrast; electron beam from tungsten filament accelerated by high voltage and focused by a magnetic field |
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Artifacts |
structure seen in a microscope image that results from the coagulation or precipitation of materials that had no existence in the living cell |
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Freeze Fracture Replication |
frozen tissue is fractured with a knife |
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Freeze-etching |
a layer of ice is evaporated from the surface of the specimen prior to coating it with heavy metal |
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Scanning electron microscope (SEM) |
form images from electrons bounced off the specimen surface; specimens are dehydrated by critical-point drying and then coated with of layer of carbon, then gold; wide range of magnification and focus |
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Atomic Force Microscopy (AFM) |
high resolution scanning instrument; provides an image of each individual molecule as it is oriented in the field; can obtain rapid sequential images |
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Half-life |
measures instability of radioisotopes; half of the radioactive material disintegrates in a given amount of time |
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Liquid Scintillation Spectrometry |
Scintillants absorb the energy of an emitted particle and release it in the form of light |
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Cell Culture |
cells can be obtained in large quantities; most cultures contain a single cell type; cell differentiation can be studied |
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Primary Culture |
cells are obtained directly from the organism |
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Secondary Culture |
derived from a previous culture |
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Cell Line |
cells with genetic modifications that allow them to grow indefinitely |
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Differential centrifugation |
facilitates the isolation of particular organelles in bulk quantity |
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Ion-exchange chromatography |
uses ionic charge as a basis for purification |
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Gel filtration |
separates proteins by weight * largest come out first! |
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Affinity chormatography |
isolates protein from a mixture using a specific ligand |
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Yeast two-hybrid system |
determines protein-protein interactions antibodies establish protein interactions by co-precipitation
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Two Dimensional Gel Electrophoresis |
separates proteins on the basis of both isoelectric focusing and molecular weight |
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X-ray crystallography |
-uses crystals -diffraction pattern provides information about protein structure -useful for studying proteins and nucleic acids |
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Polyacrylamide Gel Electrophoresis |
separation is based on size |
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Southern Blot |
based upon DNA hybridization |
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Northern Blot |
based upon RNA-DNA hybridization |
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Hybridization can be used to determine |
the degree of similarity between samples |
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Nucleic acid hybridization |
based on the ability of two complementary DNA strands to form a double stranded hybrid |
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-DNA first cut with restriction enzymes -various ways, ex. sticky ends -two components of a recombinant DNA are linked by DNA ligase |
Formation of recombinant DNAs |
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Vectors for cloning DNA |
bacterial plasmids and viruses |
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Applications of PCR |
-amplifying DNA for cloning or analysis -testing for presence of specific DNA sequences -comparing DNA molecules -quantifying DNA or RNA templates |
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transduction |
DNA incorporation into the genome of a non-replicating virus |
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transfection |
DNA introduced into cultured cells |
