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28 Cards in this Set
- Front
- Back
Microscopy |
•View objects that are not visible to the naked eye Types Of microscopes •Light •Electron •Probe |
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Magnification |
•Increase In the size of a projected image •Caused By refraction of light through lens •Refraction Changes the focal point -change in magnification |
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Resolution |
•Distinguish Points of an object close to each other •Distance is the minimum distance between distinguishable points •Directly correlated to the wavelength of the electromagnetic radiation |
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Contrast |
•Difference In luminance or color that allow objects to be distinguishable Examples •Staining •Changing Light phases - increase the differences in amplitude of light |
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Light (Optical) Microscopy |
•Electromagnetic Radiation (light, UV) to create a magnified image of the object •Brightfield microscope •Darkfield microscope •Phase Microscope •Fluorescence Microscope •Confocal Microscope |
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Bright Field Microscopy |
•Contrast is formed when different areas of the specimen w/various density absorb different amounts of light •Illumination from below the specimen •Objective Lens projects an image between the objective & ocular lens •Ocular Lens further magnify that image |
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Bright Field Microscopy: Simple Microscopes? |
Single Line for increasing magnification & resolution |
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Bright Field Microscopy: Compound Microscopes? |
Uses Multiple lens to increase magnification & resolution |
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Dark Field Microscope |
•Suitable For live or unstained specimens •Illumination From below the specimen •Condenser Lens focus light onto the specimen at oblique angle •light scattered by the specimen will be transmitted to the objective lens •light that did not hit the specimen will miss the lens and not collected |
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Phase Contrast Microscopy |
•Takes advantage of the wave properties of light •Light Scattered by the specimen will have different amplitude & phase compare to light absorbed by the specimen •Special Equipment required to detect these phase changes |
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Fluorescence Microscopy |
•Substances absorb electromagnetic radiation outside of the visible spectrum & releases the energy back as visible light •Utilizes this property to increase contrast •Uses fluorescent dye or antibodies & UV light to make specimens fluoresce |
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Confocal Microscope |
•Uses fluorescence to increase contrast •Point Illumination of 1 plane of the specimen •Pinhole Aperture limits light collected by the lens to those that are in focus with the plane being studied |
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Electron Microscopy |
•Beam Of electron instead of electromagnetic radiation to illuminate the specimen -TransmissionElectron Microscopes -ScanningElectron Microscopes |
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Transmission Electron Microscope |
•Transmit high energy electron beam through the specimen •Electrons From the beam are either scattered, refracted or transmitted through unaffected •Specimens Must be very thin (100 nm) |
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Scanning Electron Microscope |
•Scans The specimen w/a beam of high energy electrons •Electrons from the beam hits specimen, lose energy through a variety of ways •Loss of energy can be detected & used to create an image |
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Probe Microscopy |
•Physical probe scan & generate an image •A tip of several nanometer in size |
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Staining |
•Allow microorganisms to become visible •Increases Contrast |
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Preparation For Staining |
•Smear And Fix •Spreads the organisms onto a thin film •Fixing Maintains structure of the organism & causes to attach to slide |
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Simple Stains |
Uses 1 stain |
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Differential Stains |
More than 1 stain are needed to stain the microorganisms |
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Most common Differential stains? |
Gram stain & acid fast |
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GramStain process? |
•Primary stain (e.g. Crystal Violet) •Treated/mordant (e.g. Iodine) to bind the primary stain (makes the dye less soluble) •Ethanol Or Acetone used to dissolve the thin cell wall of the gram negative cells •Counterstain(e.g. Safranin) |
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Acid-Fast Stain process? |
•Primary stain (carbolfuchsin) while heating the slide •Cool & Treat w/HCl to decolourize the smear •Counterstain with methylene blue •Prevents the uptake of Gram stains •Cover Smear with blotting paper |
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Most common Acid-Fast Stain? |
Mycobacterium because of their waxy lipids in their cell wall |
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Endospore Staining |
•Resistant To uptake of most stains •Use Heat to facilitate the uptake of malachite green •Counterstain/safranin |
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Negative Stains |
•Does not stain the capsule well •Stains the interior of the bacteria and the surrounding regions •Leaves A clear halo around the bacteria |
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Taxonomy |
•Domain - (Bacteria,Archaea Eukaryota) •Kingdom •Phylum •Class •Order •Family •Genus - proteins •Species - Tiger, lion not same species |
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What is the modern Taxonomic classifications? |
Based Mainly on comparing organisms at a molecular level |