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56 Cards in this Set
- Front
- Back
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what is adipose?
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it is a form of connective tissue
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what does adipocytes do?
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sythesize and store fat
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what happens to the nucleus of an adipocyte as lipid accumulates in cell?
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the nucleus becomes flattened.
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When is not fat preserved?
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in sections processed routinely for paraffin embedding.
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what happens when lipids are preserved by formalin?
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lipids are preserved by formalin, but not made insoluble.
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what will happen when adipose tissue is stored in formalin?
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It will result in a gradual loss of lipids.
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what will make lipids insoluble?
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Osmium tetroxide will chemically combine with lipids to make them insoluble.
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What can adipose tissue be demonstrated with?
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formalin fixed frozen sections, fresh frozen sections, osmium tetroxide fixed paraffin embedded sections or sections embedded in insoluble.
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what does Oil Red O for neutral demonstrate?
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demonstrates neutral lipids in frozen sections.
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What does Oil Red O for Neutral fats demonstrate?
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can demonstrate fat in abnormal places and identify tumors of lipid origin. Also lipfuchsin on ciroid.
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What kind of method is Oil Red O?
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it is a physical method of staining.
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Is the dye more soluble in tissue or solvent?
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The dye is more soluble in the tissue lipid than in the solovent in which it is dissolved.
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In an Oil Red O what is critical?
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The solvent used is critical.
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what removes a minimal amount of lipid?
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isopropanol
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what does propylene glyclol not remove?
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it removes no lipids.
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what are sections cut at in an Oil Red O?
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Frozen sections are cut at 10 microns.
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what happens if the tissue is not fixed in formalin prior to sectioning?
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the section is fixed in 40% formaldehyde.
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what can be used to improve microtomy when doing and oil Red O?
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formalin fixed tissue may be infiltrated with 30% sucrose to improve microtomy.
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what kind of mounting medium must be used when doing a Oil Red O stain?
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aqueous mounting media.
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what can be used to seal the edges of an Oil Red O stain?
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Nail polish can be used on the edges of the slide.
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what kind of hematoxylin can be used as a counterstain of an Oil Red O stain?
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alcohol free hematoxylin
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what are the results of an Oil Red o stain?
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fat is intense red and nuclei is blue.
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what should you know about an Oil Red O stain?
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Do not put pressure on coverslip as fat droplets, will be displaced from their original location.
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What does Sudan Black in Propylene Glycol demonstrate?
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Demonstrates neutral lipids in tissue sections.
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What is Sudan Black soluble in?
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Sudan Black is soluble in phospholids and somewhat soluble in cerebrosides.
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Sudan Black in Propylene glycol is also used where?
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in hematology.
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What kind of dye is Sudan Black?
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it is a basic dye that will combine with acidic groups in compound lipids such as phospholipids.
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What are sections cut at in a Sudan Black?
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frozen sections are cut at 10 microns.
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Is Sudan Black a physical or chemical?
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It is both physical and chemical, but mainly physical.
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what kind of mounting medium should be used when doing a Sudan Black?
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aqueous mounting medium.
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what are the results of a Sudan Black stain?
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fat is blue-black and nuclei is red.
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What does Osmium Tetroxide demonstrate?
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lipids can be demonstrated following routine processing.
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What kind of method is Osmium Tetroxide?
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a chemical method, the osmium tetroxide combines with the lipid imparting a black color to the fat.
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What does the Osmium Tetroxide do to the fat compound?
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it makes the fat compound insoluble and can be processed for paraffin embedding.
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Osmium tetroxide does not process fast, so what should happen to the tissue?
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It should be cut at 2 microns to assure penetration.
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When using Osmium tetroxide, processing should begin at ?
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70% alcohol and large amounts of fat are not fixed. also cytoplasmic stains are affected.
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Where should you use Osmium Tetroxide?
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Under a fume hood. It has a PEL of .002 ppm.
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what can happen when using Osmium Tetroxide, if not careful?
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Vapors can fix nasal mucosa or conjunctiva of the eye.
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What is used as a differentiator when staining with Osmium Tetroxide?
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periodic acid is used to clear the background and leave the fat stained black.
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when using Osmium Tetroxide, when does staining take place?
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Staining takes place the same time fixation does.
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After using Osmium Tetroxide for fixation and staining what do you do?
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After routine processing an H&E can be done or other special stains, such as a trichrome.
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What are the results of Osmium Tetroxide?
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Fat is stained black and other tissue elements are stained according to what other method was used.
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What are urate crystals considered to be?
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endogenous deposits.
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Where are the urate crystals deposited?
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Urate crystals are deposited in tissue on around joints in patients with gout.
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What are the urate deposits in tissue called?
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Gouty tophi.
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Why must urate crystals be fixed in alcohol.
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Because they are soluble in water.
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When does processing begin?
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It will begin in absolute alcohol.
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Why is it that urate crystals can be seen by polarizing microscopy or by an argentaffin reaction?
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Because urate crystals are birefringent.
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What demonstrates urate crystals (gouty tophi)?
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A modified Gomori Methenamine-Silver method.
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What do the urate crystals react with?
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Silver, which then is reduced to its metallic form.
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When doing a modified GMS for urates, what are the urate crystals fixed in?
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the urate crystals must be fixed in alcohol. Slides are brought through alcohol for staining.
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what are slides incubated in?
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Methenamine silver until urate crystals are black.
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In a GMS for urate crystals, after sections are deparaffinized, what should you do next?
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rinse in absolute alcohol and do not hydrate then place slides in methenamine-silver.
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what do you counter stain with when doing a modified GMS?
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After removing the unreduced silver with sodium thiosulfate, counterstain with Light Green
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what are the results of a modified GMS when staining for urate crystals?
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Urate crystals are black and background is green.
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What reduces the urates crystals to its metallic form?
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Argentaffin properties of urates will reduce the silver to its metallic form.
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