Portage Learning: Microbiology, Module 3 – MICROSCOPY

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Portage Learning: Microbiology, Module 3 – MICROSCOPY micrometer ✔✔one millionth of a meter nanometer ✔✔one billionth of a meter resolution and contrast ✔✔two critical factors that i... nfluence our ability to see an object resolution ✔✔the distance between two objects at which the objects still can be seen as separate greater ✔✔the closer two objects are to each other the __________________ the resolution requirement contrast ✔✔the difference in light absorbance between two areas (objects) lower ✔✔the ________________ the contrast between an object and its background, the harder it will be to see the object bright field microscope ✔✔simplest form of light, or optical, microscopy/light, most often emitted from a standard halogen bulb, enters the microscope from the base (bottom) and is reflected via mirrors towards the sample condenser ✔✔before the light reaches the sample, it first passes through a ________________ converging the light beams into a focused area on the sample iris diaphragm ✔✔controls the amount of light that passes through the sample and into the objective lens objective lens ✔✔the lens closest to the sample and yields the greatest amount of magnification directly proportional ✔✔the degree of magnification is ______________________ to the amount of light needed/to image samples clearly at higher magnifications, more light is required ocular lens ✔✔eyepiece 10x ✔✔most common power of ocular lens total magnification ✔✔objective x ocular lens= staining ✔✔required due to the limitation of resolution on unstained cells, (i.e.) often the flat and transparent regions of a cell may appear invisible under bright field conditions/with various dyes, these regions can become labeled and thus visualized. phase contrast microscope ✔✔able to visualize certain structures that would otherwise be invisible/ can provide detailed images of live cells without staining./uses specialized condensers and objectives, it amplifies the slight differences between cells and the surrounding medium (background) to make the cells highly distinguishable/can be used to visualize cell movements dark field microscope ✔✔can be used to greatly increase the contrast between a specimen and background, resulting in a dark backgro [Show More]

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