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127 Cards in this Set
- Front
- Back
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An example of an additive fixation is one that contains:
a) mercuric chloride b) acetic acid c) ethyl alcohol d) acetone |
a) mercuric chloride
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When compared with tissue fixed in formalin, tissue fixed in zinc-formalin will show:
a) better ultrastructural preservation b) decreased immunoreactivity c) increased enzyme activity d) superior nuclear detail |
d) superior nuclear detail
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Micoscopic examination of an H&E-stained section fixed in formalin shows marked nuclear bubbling. One most often sees this artifact if the specimen is processed following:
a) underfixation b) prolonged fixation c) microwave fixation d) frozen sectioning |
a) underfixation
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Microscopic evaluation of H&E-stained sections from a surgically removed small bowel specimen show an absence of much of the epithelium in otherwise normal tissue. This most likely resulted from:
a) mechanical trauma b) delayed fixation c) ulceration d) poor choice of fixative |
b) delayed fixation
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A specimen of kidney must be shipped to another city for immunofluorescence studies. The specimen should be placed in:
a) saline b) Michel solution c) buffered formalin d) Orth solution |
b) Michel solution
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In a certain project it is important to use a fixative that contains acetic acid yet stabilizes erythrocyte membranes. One fixative that could be used is:
a) Zenker solution b) Bouin solution c) Gendre solution d) Hollande solution |
d) Hollande solution
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When a microwave oven is used for fixation, the most critical factor is the:
a) preparation of the formalin solution b) use of glass containers c) control of the temperature d) osmolality of the fixation solution |
c) control of the temperature
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To adequately remove the calcium in a specimen containing areas of microcalcifications, the tisse could be fixed in:
a) Hollande solution b) NBF c) B-5 solution d) Zamboni solution |
a) Hollande solution
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Which of the following fixatives contains copper acetate?
a) Hollande b) Bouin c) Gendre d) Zamboni |
a) Hollande
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A specimen is submitted with the statement that it was fixed if formalin. Microscopic sections show marked lysis of erythrocytes. This indicates that the fixative most likely was:
a) prepared with too much formalin b) buffered above neutrality c) acetified with acetic acid d) not formalin |
c) acetified with acetic acid
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Fixatives are classified as additive because of the:
a) addition of several chemicals to the solution b) addition, or binding of the fixative, to tissue proteins c) additional reactions occurring with longer fixation d) additional reactive tissue sites available for dye binding |
b) addition, or binding of the fixative, to tissue proteins
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The only kidney biopsy tissue available has been fixed in phosphate-buffered glutaraldehyde for 2 hours and then placed in phosphate buffer solution. If a portion of this tissue is processed for light microscopy, sections would most likely show:
a) very poor glomerular preservation b) decreased uptake of hematoxylin c) lysis of cytoplasmic elements d) nonspecific PAS staining |
d) nonspecific PAS staining
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Uric acid crystals are preserved only when tissue is fixed in:
a) absolute alcohol b) NBF c) Orth solution d) Zamboni solution |
a) absolute alcohol
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Improper preservation of issue will result if there is:
a) a delay in fixation b) rapid penetration of the fixing fluid c) prolonged storage following formalin fixation d) rapid dehydration, clearing, embedding, and sectioning |
a) a delay in fixation
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A good fixative will:
a) render cell constituents soluble b) minimize differences in tissue refractive indices c) protect tissue against alteration by subsequent processing d) minimally affect tissue metabolic processes |
c) protect tissue against alteration by subsequent processing
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The function of methanol in commercial formalin solutions is to:
a) retard the polymerization of formaldehyde b) prevent the formation of formic acid c) stabilize the formalin at a basic pH d) permit the storage of formalin at room temperature |
a) retard the polymerization of formaldehyde
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The subsequent demonstration of chromaffin granules requires which of the following fixatives?
a) Orth b) Bouin c) B-5 d) formalin |
a) Orth
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In electron microscopy, Zamboni fluid, glutaraldehyde, and osmium tetroxide function as:
a) dehydrating agents b) clearing agents c) embedding media d) fixatives |
d) fixatives
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Tissue will remain unfixed if placed in:
a) potassium dichromate b) sodium borate c) osmium tetroxide d) zinc chloride |
b) sodium borate
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Bouin solution is contraindicated for:
a) small tissue biopsies b) tissue intended for subsequent trichrome stains c) tissue to be stained by the Feulgen reaction d) routine tissue sections |
c) tissue to be stained by the Feulgen reaction
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Formalin pigment can be removed from tissue sections by treatment with 10%:
a) hydrochloric acid in 70% alcohol b) nitric acid in 70% alcohol c) sulfuric acid in 70% alcohol d) ammonium hydroxide in 70% alcohol |
d) ammonium hydroxide in 70% alcohol
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Stock neutralized formalin is prepared in the laboratory by storing the solution over a layer of calcium carbonate.The solution withdrawn from this stock container will:
a) become acidic b) become alkaline c) remain neutral d) exhibit metachromasia |
a) become acidic
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Microscopic evaluation reveals a very poorly-stained H&E section of spleen. These results will be difficult to remedy if the problem is:
a) poor fixation b) improper sectioning c) poor staining d) incorrect section placement |
a) poor fixation
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To make a 10% formalin solution, how many mL of water should be added to 300mL of 37% to 40% formaldehyde solution?
a) 1800 b) 2500 c) 2700 d) 3600 |
c) 2700
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One action of acetic acid is to:
a) exert a shrinking effect on tissue b) render nucleoprotein acidophilic c) form salt linkages between protein chains d) coagulate nucleoproteins |
d) coagulate nucleoproteins
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Aldehyde fixatives are used for electron microscopy preparation because they:
a) are readily available b) visibly stain tissue c) preserve cell ultrastructure d) coagulate tissue lipids |
c) preserve cell ultrastructure
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A fixative containing potassium dichromate:
a) is suitable when histochemical techniques are planned b) will result in excellent subsequent silver staining c) is preferred for the preservation of argentaffin cells d) will make tissue more receptive to eosin staining |
d) will make tissue more receptive to eosin staining
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If mercuric chloride is used alone for fixation, it will:
a) leave tissue proteins uncoagulated b) produce a very acidic solution c) penetrate poorly and cause excessive shrinkage d) decrease tissue affinity for stains |
c) penetrate poorly and cause excessive shrinkage
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Tissue stored for long periods of time in unbuffered formalin or in acetate-buffered formalin may show brown, crystalline pigment in stained sections. To remove this pigment prior to staining it is necessary to treat the section in:
a) saturated alcoholic picric acid b) alcoholic lithium chloride c) iodine and sodium thiosulfate d) potassium permanganate and oxalic acid |
a) saturated alcoholic picric acid
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For good fixation of specimens for electron microscopy, it is recommended that the tissue segment be no larger than:
a) 1mm b) 2mm c) 1cm d) 2cm |
a) 1mm
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Waxes that are commonly used in the preparation of tissue sections for light microscopic evaluation are NOT used in electron microscopy because tissues prepared in wax:
a) cannot be stained with osmium tetroxide b) are too hard for thin sectioning c) are not transparent d) will not withstand an electron beam |
d) will not withstand an electron beam
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Following fixation with Bouin solution, tissue should be washed with:
a) absolute alcohol b) 50% to 70% alcohol c) 20% to 40% alcohol d) saline solution |
b) 50%-70% alcohol
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Zenker fluid is the recommended fixative for subsequent:
a) PTAH staining b) frozen staining c) hemosiderin preservation d) erythrocyte demonstration |
a) PTAH staining
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The acetic acid present in some fixatives:
a) coagulates and shrinks cytoplasmic proteins b) dissolves some cytoplasmic organelles and deposits c) penetrates tissue very slowly and incompletely d) hardens the tissue markedly |
b) dissolves some cytoplasmic organelles and deposits
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Absolute ethanol is a poor choice for the fixation of:
a) glycogen b) pigments c) lipids d) blood smears |
c) lipids
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Which of the following fixatives may give false-positive results in carbohydrate demonstration?
a) NBF b) Bouin solution c) Gendre solution d) glutaraldehyde |
d) glutaraldehyde
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It is necessary to adjust the pH of most formalin solutions because of the presence of:
a) methanol b) formic acid c) paraformaldehyde d) carbon dioxide |
b) formic acid
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The rate of fixation varies with the fixative and is also dependent upon:
a) grossing pathologist's preference b) expected completion time of the report c) anticipated special stains d) temperature of the fixative |
d) temperature of fixative
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Carnoy solution is recommended for the preservation of:
a) acid-fast bacilli b) nucleic acids c) lipids d) red blood cells |
b) nucleic acids
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Orth solution contains all of the following except:
a) potassium dichromate b) mercuric chloride c) sodium sulfate d) 37% to 40% formaldehyde |
b) mercuric chloride
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Formalin pigment is generally created in tissues fixed in formalin when the pH:
a) rises above 6 b) falls below 6 c) is buffered to neutrality d) is 7.2 |
b) falls below 6
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A universal fixative used for routine purposes thatallows a broad spectrum of staining procedures is:
a) Zenker fluid b) Zamboni PAF c) 10% NBF d) Carnoy solution |
c) 10% NBF
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One advantage of fixing tissue in Zenker solution is that:
a) the prolonged treatment keeps the tissue soft and pliable b) Zenker-fixed tissues stain brilliantly c) artifactual pigments are not formed d) washing after fixation is not required |
b) Zenker-fixed tissues stain brilliantly
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A tissue section was not initially placed in the fixative required for a staining procedure. However, after deparaffinization and rehydration, sections frequently can be stainied anyway if they are:
a) soaked in solution of lithium carbonate prior to staining b) revitalized by washing in a solution of sodium bisulfate c) post-fixed in the appropriate fixative prior to stianing d) treated with hydrogen peroxide |
c) post-fixed in the appropriate fixative prior to staining
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Helly fluid contains all of the following EXCEPT:
a) mercuric chloride b) potassium dichromate c) sodium sulfate d) glacial acetic acid |
d) glacial acetic acid
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Fixation in Bouin solution is:
a) recommended for the Feulgen reaction b) excellent for ultrastructural preservation c) the cause of considerable swelling of tissue d) frequently used for endocrine tissues |
d) frequently used for endocrine tissues
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B-5 fixative contains:
a) mercuric chloride, sodium acetate, and glacial acetic acid b) mercuric chloride, potassium dichromate, and glacial acetic acid c) mercuric chloride, sodium acetate, and 37% to 40% formaldehyde d) mercuric chloride, potassium dichromate, and 37% to 40% formaldehyde |
c) mercuric chloride, sodium acetate, and 37% to 40% formaldehyde
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Pigment caused by mercury-containing fixatives can be removed from tissues by:
a) saturated alcoholic picric acid b) iodine-sodium thiosulfate c) washing in running water d) potassium hydroxide in water |
b) iodine-sodium thiosulfate
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Which of the following fixatives has a mordanting effect on tissue?
a) Carnoy solution b) 10% calcium formalin c) absolute alcohol d) Zenker solution |
d) Zenker solution
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Tissue should be placed in a suitable fixative immediately after removal from the body to:
a) prevent decomposition due to enzymatic activity b) permit the dehydrant to function properly c) inhibit cross-linking of tissue proteins d) stabilize tissue carbohydrates |
a) prevent decomposition due to enzymatic activity
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Baker calcium-formalin fixative is recommended for the best preservation and subsequent demonstration of:
a) glycogen b) phospholipids c) amyloid d) estrogen receptors |
b) phospholipids
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For most fixatives, the volume of fixing fluid in relation to the volume of tissue should be:
a) 2 to 5 times b) 6 to 9 times c) 10 to 14 times d) 15 to 20 times |
d) 15 to 20 times
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Ultrastructural preservation will be very poor following fixation in:
a) Zamboni PAF b) 2% buffered glutaraldehyde c) osmium tetroxide d) 10% aqueous formalin |
d) 10% aqueous formalin
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The fixation of tissue begins at the:
a) center and proceeds outward b) center and proceeds inward c) periphery and proceeds outward d) periphery and proceeds inward |
d) periphery and proceeds inward
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Zinc-formalin fixatives:
a) give poor ultrastructural preservation b) can be used to preserve enzymes c) result in poor nuclear detail d) will not coagulate tissue proteins |
a) give poor ultrastructural preservation
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Zamboni PAF refers to a fixative containing:
a) potassium dichromate, acetic acid, and formaldehyde b) potassium aluminum sulfate and paraformaldehyde c) buffered picric acid and formaldehyde d) picric acid, acetic acid, formaldehyde |
c) buffered picric acid and formaldehyde
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Excess fixative must be removed from specimens before placing them in dehydrating solutions if the fixative contains:
a) glutaraldehyde b) mercuric chloride c) picric acid d) potassium dichromate |
d) potassium dichromate
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The preferred fixative when tissue is to be stained for the prescence of simple fats is:
a) Zenker b) Helly c) Hollande d) NBF |
d) NBF
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Which of the following is recommended for central nervous system tissues to be stained with the Cajal technique?
a) neutralized formalin b) formalin ammonium bromide c) paraformaldehyde d) alcoholic formalin |
b) formalin ammonium bromide
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When osmium tetroxide is used as a fixative in histology, it:
a) destroys lipids b) interferes with staining c) leaves tissue very soft d) distorts cell membranes |
b) interferes with staining
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The breakdown of tissue due to enzyme activity is called:
a) polymerization b) putrefaction c) autolysis d) osmosis |
b) autolysis
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The fixative of choice for the demonstration of urate crystals is:
a) NBF b) absolute alcohol c) Bouin solution d) Zenker solution |
b) absolute alcohol
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A good fixative for routine use is one that:
a) makes tissue more permeable to fluids b) is hypotonic to the tissue constituents c) enhances putrefaction of tissue components d) promotes tissue autolysis |
a) makes tissue more permeable to fluids
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A pigment caused by chromate-containing fixatives can be prevented by treating the tissue prior to processing with:
a) running water b) iodine c) picric acid d) potassium permanganate |
a) running water
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When fixing tissue with formaldehyde or glutaraldehyde, proper enzyme activity and preservation of structure depend upon all of the following EXCEPT:
a) pH b) time and temperature c) concentration and purity of the reagent d) type of tissue |
d) type of tissue
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Formic acid present in commercial formalin solutions may:
a) facilitate pigment formation b) precipitate hemosiderin c) promote staining d) cause tissue shrinkage |
a) facilitate pigment formation
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Carnoy solution is a combination of which of the following chemicals?
a) absolute alcohol, acetone, and glacial acetic acid b) cedarwood oil, absolute alcohol, and glacial acetic acid c) acetone, chloroform, and absolute alcohol d) chloroform, glacial acetic acid, and absolute alcohol |
d) chloroform, glacial acetic acid, and absolute alcohol
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When staining chromaffin cells for the diagnosis of pheochromocytoma, it is necessary to fix the tissue in a:
a) mercury fixative b) primary chromate fixative c) formalin fixative d) picric acid fixative |
b) primary chromate fixative
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When liver tissue is fixed with 2% to 3% glutaraldehyde:
a) protein is only partially perserved b) the penetration rate is very rapid c) a chemical reaction occurs with lipids d) the ultrastructure is preserved |
d) the ultrastructure is preserved
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A poor fixative is characterized by:
a) the absence of shrinking or swelling of tissue b) inactivation of tissue enzymes c) slow tissue penetration d) the absence of distortion or dissolution |
c) slow tissue penetration
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Which of the following fixatives requires washing with water before processing?
a) Carnoy b) Bouin c) 10% formalin d) Zenker |
d) Zenker
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Bouin solution contains all of the following EXCEPT:
a) picric acid b) absolute alcohol c) 37% to 40% formaldehyde d) glacial acetic acid |
b) absolute alcohol
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Coagulant fixatives:
a) change the spongework of proteins into meshes b) produce fewer artifacts than noncoagulant fixatives c) act very slowly to fix tissues d) leave protein linkages unaffected |
a) change the spongework of proteins into meshes
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The breakdown of tissue by bacterial action is called:
a) autolysis b) putrefaction c) denaturation d) oxidation |
b) putrefaction
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When ultrastructural preservation is of the utmost importance, the fixative used should have a pH of:
a) 6.8 to 7.0 b) 7.2 to 7.4 c) 7.6 to 7.8 d) 8.0 to 8.2 |
b) 7.2 to 7.4
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A fixative that produces a diffuse brownish black pigment is:
a) Bouin b) Carnoy c) Zenker d) alcohol |
c) Zenker
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For the BEST preservation of staining properties during long-term storage, tissues should be stored in:
a) buffered formalin b) 10% formal-saline c) 70% ethanol d) Zamboni solution |
c) 70% ethanol
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Ethanol is useful as a fixative because it:
a) rapidly dehydrates tissue b) increases tissue basophilia c) stabilizes red cell membranes d) preserves glycogen very well |
d) preserves glycogen very well
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Mercuric chloride pigment may be removed from tissue by:
a) treating sections with an iodine-sodium thiosulfate sequence b) using limonene clearing agent on the tissue processor c) rinsing sections with 50% to 70% alcohol d) washing sections with running water |
a) treating sections with an iodine-sodium thiosulfate sequence
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To prevent the formation of formalin pigment in tissues, formalin should be:
a) heated b) cooled c) buffered d) acidified |
c) buffered
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Which of the following fixatives should be used for specimens that are to be mailed?
a) 10% NBF b) Bouin solution c) Helly solution d) Zenker solution |
a) 10% NBF
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A biopsy that was placed in water by mistake is submitted to the laboratory. This mistake most likely will cause:
a) mushy sections b) swollen or ruptured cells c) hardening of the tissue d) no appreciable changes |
b) swollen or ruptured cells
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Sections of a breast carcinoma were fixed in a saline solution in the microwave oven. Microscopic examination of the H&E-stained sections show marked pyknotic, overstained nuclei. The staining results were most likely caused by the:
a) use of saline for fixation b) solution temperature exceeding 55⁰C c) use of plastic containers in the microwave d) presence of carcinoma in the breast tissue |
b) solution temperature exceeding 55⁰C
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An unknown pigment in a tissue section that can be bleached with a saturated alcoholic solution of picric acid is most likely:
a) melanin pigment b) formalin pigment c) hemosiderin d) mercury pigment |
b) formalin pigment
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The formaldehyde in Helly solution:
a) causes reduction of some chemicals in the solution b) coagulates and denatures tissue proteins c) prevents turbidity and precipitate formation d) eliminates the need for post-fixation washing |
a) causes reduction of some chemicals in the solution
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Formaldehyde solutions for routine use are most commonly buffered by:
a) monobasic and dibasic phosphates b) sodium acetate and acetic acid c) s-collidine and hydrochloric acid d) sodium barbitol and sodium hydroxide |
a) monobasic and dibasic phosphates
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If asked to cut cryostat sections of tissue fixed in Zenker solution, the histotechnologist should:
a) section the tissue as is b) explain that frozen sections containing mercuric chloride cannot be made c) treat the tissue with iodine, hypo, and water before freezing d) use a solution of 30% sucrose to infiltrate the tissue before freezing |
c) treat the tissue with iodine, hypo, and water before freezing
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One characteristic of Zamboni fixative is that it:
a) does not stabilize cellular proteins b) is recommended for electron microscopy c) is easily destroyed by tissue fluids d) must be followed by osmium tetroxide |
b) is recommended for electron microscopy
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The best fixative for blood smears is:
a) Bouin solution b) Carnoy solution c) B-5 solution d) methanol |
d) methanol
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When used as a secondary fixative, osmium tetroxide should be:
a) used after lead citrate b) heated prior to use c) combined with alcohol d) used under a chemical hood |
d) used under a chemical hood
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Which of the following fixatives is recommended for use in lipid histochemistry?
a) Zenker solution b) acetone c) formalin-saline d) calcium-formalin |
d) calcium-formalin
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In the Cajal method for demonstrating astrocytes, sections of brain should be fixed in formalin that contains:
a) sodium acetate b) ammonium bromide c) mercuric chloride d) calcium chloride |
b) ammonium bromide
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Hollande solution is a modification of which of the following fixatives?
a) Helly solution b) Orth solution c) Carnoy solution d) Bouin solution |
d) Bouin solution
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Tissue fixed in which of the
following solutions must be post-treated for mercuric chloride pigment? a) B-5 b) Zamboni c) Carnoy d) Orth |
a) B-5
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Acetone is recommended for the primary fixation of:
a) prostate tissue for immunohistochemistry b) kidney tissue for fluorescent antibody techniques c) muscle tissue for enzyme histochemistry d) brain tissue for the diagnosis of rabies |
d) brain tissue for the diagnosis of rabies
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Fresh unfixed tissue can be stored safely for a short time by:
a) keeping it in a freezer b) wrapping it in saline-moistened gauze and refrigerating it c) placing it in physiological saline at room temperature d) leaving it in a dry specimen container on the counter with a note to the histologist |
b) wrapping it in saline-moistened gauze and refrigerating it
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Zenker solution contains:
a) mercuric chloride, potassium dichromate, and formaldehyde b) mercuric chloride, chromic acid, and formaldehyde c) mercuric chloride, potassiume dichromate and acetic acid d) potassium dichromate, formaldehyde, and acetic acid |
c) mercuric chloride, potassium dichromate, and acetic acid
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One characteristic of Bouin solution is that it:
a) penetrates poorly b) destroys delicate structures c) mordants connective tissue stains d) preserves erythrocyes |
c) mordants connective tissue stains
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The fixation of tissue by physical methods can be demonstrated by the use of:
a) microincineration b) microwaves c) frozen sections d) alcohol |
b) microwaves
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Fixation in Carnoy solution will result in:
a) swelling of the tissue b) preservation of most cytoplasmic structures c) superior staining of amyloid and Congo red d) good preservation of red blood cells |
c) superior staining of amyloid and Congo red
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The recommended fixative for tissue suspected of containing spirochetes is:
a) 10% NBF b) Bouin solution c) Zenker solution d) Helly solution |
a) 10% NBF
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Which of the following is frequently added to formalin solutions to help preserve immunoreactivity?
a) glycerin b) sodium acetate c) zinc salts d) chromates |
c) zinc salts
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Which of the following fixatives is recommended for both the Heidenhain and Mallory aniline blue stains?
a) Orth fluid b) NBF c) Zenker fluid d) absolute alcohol |
c) Zenker fluid
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A fixative used for the preservation of some enzymes is:
a) Bouin solution b) B-5 solution c) acetone d) isopropanol |
c) acetone
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A common reason for adding acetic acid to fixatives is it:
a) coagulate proteins b) reduce shrinkage c) preserve carbohydrates d) change the pH |
b) reduce shrinkage
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Formaldehyde acts as a fixative by:
a) uncovering acid groups b) coagulating proteins c) cross-linking proteins d) rupturing peptide linkages |
c) cross-linking proteins
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When it is known prior to fixation that a distinction must be made between collagen and muscle, the preferred fixative is:
a) NBF b) Orth fluid c) absolute alcohol d) Bouin fluid |
d) Bouin fluid
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For optimum staining results, Bouin or Zenker fixation is recommended for:
a) the Wilder reticulum techniques b) most trichrome stains c) the Weigert elastic tissue stain d) any silver stain |
b) most trichrome stains
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In Bouin fixative, the shrinking effect produced by one component is balanced by the swelling effect of:
a) formalin b) acetic acid c) osmium tetroxide d) potassium dichromate |
b) acetic acid
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10% formalin is equivalent to what percentage of paraformaldehyde?
a) 40 b) 10 c) 4 d) 1 |
c) 4
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The use of formalin as a fixative in the mircowave oven:
a) is a possible explosive hazard b) produces toxic vapors c) degrades plastic cassettes d) corrodes fixed tissues |
b) produces toxic vapors
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Which of the following renders fat insoluable for subsequent processing?
a) picric acid b) osmium tetroxide c) chloroform d) formldehyde |
b) osmium tetroxide
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The presence of acetic acid in fixatives produces:
a) cell shrinkage b) red cell destruction c) protein coagulation d) lipid preservation |
b) red cell destruction
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Microscopic review of a formalin-fixed tissue section demonstrates a fine, brown-black artifactual pigment. This artifact most likely could have been prevented by:
a) placing the tissue in formalin immediately after removal b) preparing the solution just before use c) washing the tissue after fixation d) making the solution neutral |
d) making the solution neutral
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When osmium tetroxide is used as a fixative, it:
a) must be used after a primary fixative b) should be used in a hood c) should be more hypotonic to tissue d) must be made basic |
b) should be used in a hood
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Which of the following fixative components produces shrinkage and penetrates poorly:
a) glacial acetic acid b) mercuric chloride c) potassium dichromate d) ethanol |
b) mercuric chloride
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The component in Bouin solution that causes tissue shrinkage is:
a) picric acid b) acetic acid c) mercuric chloride d) potassium dichromate |
c) mercuric chloride
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Which of the following fixatives should be selected when it is desirable to preserve erythrocytes in tissue?
a) Zenker b) Bouin c) Carnoy d) B-5 |
d) B-5
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A tissue section reveals a dark brown microcrystalline pigment that is birefringent. To remove the pigment, the section should be treated with an alcoholic solution saturated with:
a) sodium thiosulfate b) oxalic acid c) picric acid d) hydrochloric acid |
c) picric acid
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Shrinkage and distortion of tissue is greatest following fixation in:
a) Zenker fluid b) Bouin solution c) absolute alcohol d) Helly fluid |
c) absolute alcohol
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Tissue to be stained by the Warthin-Starry technique should be fixed in:
a) Zenker fluid b) saturated mercuric chloride c) formalin d) osmium tetroxide |
c) formalin
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Alcohol, rather than water, is used as the solvent in some fixatives because alcohol:
a) helps precipitate proteins b) decreases tissue shrinkage c) increases lipid preservation d) eliminates the need for dehydration |
a) helps precipitate proteins
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When preparing Helly solution, formalin should be added:
a) when other ingredients are combined b) before adding mercuric chloride c) when ready to use d) 24 hours before use |
c) when ready to use
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When fat is to be preserved, the fixative of choice is:
a) formalin b) Zenker solution c) Carnoy solution d) Bouin solution |
a) formalin
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Picric acid was used alone as a fixative for a section of liver. The tissue most likely will show:
a) extreme swelling b) excessive hardening c) an increased uptake of eosin d) hydrolyzed nucleic acids |
d) hydrolyzed nucleic acids
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The primary purpose of fixation is the:
a) preservation of carbohydrates b) coagulation of lipids c) removal of tissue fluids d) stabilization of proteins |
d) stabilization of proteins
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Bouin solution lyses erythrocytes because it contains:
a) formalin b) picric acid c) acetic acid d) alcohol |
c) acetic acid
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