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26 Cards in this Set
- Front
- Back
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A clearing agent for use in processing tissues for paraffin embedding must be miscible with the...
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dehydrant and paraffin
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Which of the following is a dehdrating agent...
a) formalin b) xylene c) benzene d) alcohol |
d) alcohol
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Dioxane is a reagent that can be used...
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for both dehydrating and clearing tissues
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A reagent that CANNOT be used for dehydrating tissue is...
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benzene
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Most commonly, the paraffin used for embedding tissues is kept at approximately...
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60 degrees C
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A disadvantage of the use of dioxane in processing tissues is that it is...
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toxic
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The chief objection to the use of xylene as a clearing agent for processing tissues is that xylene is...
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likely to harden tissue
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A good paraffin for routine use is one with a melting point of...
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55-58 degrees
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Which of the following chemicals is NOT a clearing agent...
a) chloroform b) dioxane c) ethanol d) xylene |
c) ethanol
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Overheating of the paraffin used to embed may cause...
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cracking of the block
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One advantage of the paraffin technique is that...
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serial sections are easy to obtain
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When cutting paraffin embedded tissues, if the tissue seems hard and brittle, one source of trouble is likely to be...
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overheated paraffin
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The process of removing water from tissue is called...
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dehydration
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Reagents that both clear and dehydrate are called...
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universal solvents
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Paraffin that is considered soft...
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is most useful when thick sections are desired
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When used for clearing, cedar wood oil must be followed by...
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xylene
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Paraffin is cooled as rapidly as possible after embedding tissue in order to...
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prevent the formation of large crystals
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the dehydration and clearing steps can be omitted when using...
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water soluble wax
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During microtomy it is noted that most of the tissue is very hard and shrunken. One of the first things to check to prevent its happening in the future is the...
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temperature of the infiltrating paraffin
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H and E stained sections show very uneven staining of the tissue, with poor nuclear detail. One possible cause is...
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water in the clearing agent
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Phosphate-buffered formaldehyde is used in the first two stations of the closed processor. A white precipitate is forming in the processor tubing, and the tissue is more difficult to cut than usual. One of the first things to check to correct the problem is...
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percent alcohol used as the first dehydrant
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At microtomy, formalin-fixed, paraffin-embedded kidney sections are soft and mushy. This is most likely due to...
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inadequate dehydration and clearing
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Aqueous unbuffered zinc formalin is used at the first stage on the closed processor, followed by phosphate-buffered formalin and 65% alcohol. It is noted that a white precipitate is most likely due to...
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the formation of zinc phosphate
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Tissue is processed with the following reagents...
-10% neutral-buffered formalin for 2 changes -65% alcohol for 1 change -95% alcohol for 2 changes -100% alcohol for 2 changes -aliphatic hydrocarbon for 2 changes -paraffin for 3 changes The tissue does not seem to be well cleared and infiltrated. This problem might be solved by adding... |
an aliphatic hydrocarbon and deleting one 95% alcohol
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Tissue is processed on an open processor with the following reagents...
-10% neutral-buffered formalin for 2 changes -65% alcohol for 1 change -95% alcohol for 1 change -100% alcohol for 2 changes -aliphatic hydrocarbon for 3 changes -paraffin for 3 changes At microtomy, many of the tissues are soft and mushy. One cause of the problem might be... |
high relative humidity in processor area
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Many of the zinc formalin-fixed biopsy specimens are hard and brittle and show microscopic chatter. this will result if the specimens are...
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processed incorrectly
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