Histology ASCP Exam ALL ANSWERS 2025 EDITION GUARANTEED GRADE A+

Histology ASCP Exam ALL ANSWERS 2025 EDITION GUARANTEED GRADE A+ An example of an additive is one that contains: A. Picric acid B. Acetic acid C. Ethyl alcohol D. Acetone Picric Acid 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 Superior nuclear detail Microscopic 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. Incomplete fixation B. Prolonged fixation C. Microwave fixation D. Frozen sectioning Incomplete fixation Microscopic evaluation of H&E stained sections from a surgically removed small bowel specimen shows 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 Delayed fixation 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 Michel solution A certain project requires 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 Hollande solution When the 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 fixative solution Control of the temperature To adequately remove the calcium in a specimen containing areas of microcalcification, the tissue could be fixed in: A. Hollande solution B. NBF C. B-5 solution D. Zamboni solution Hollande solution What fixative contains copper acetate? A. Hollande B. Bouin C. Gendre D. Zamboni Hollande A specimen is submitted with the statement that it was fixed in 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. Acidified with acetic acid D. Not formalin Acidified with acetic acid 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 Addition, or binding of the fixative to tissue proteins Kidney biopsy tissue 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 Nonspecific PAS staining Uric acid crystals are preserved ONLY when tissue is fixed in: A. Absolute alcohol B. NBF C. Orth solution D. Zamboni solution Absolute alcohol Improper preservation of tissue will result if there is: A. A delay in fixation B. A rapid penetration of the fixing fluid C. Prolonged storage following formalin fixation D. Rapid dehydration, clearing, embedding, and sectioning A delay in fixation A good fixative will: A. Render cell constituents soluble B. Minimize differences in tissue refractive indices C. Protect tissue against alteration during subsequent processing D. Minimally affect tissue metabolic processes Protect tissue against alteration during subsequent processing 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 room temperature storage of formalin Retard the polymerization of formaldehyde In electron microscopy, Zamboni fluid, glutaraldehyde, and osmium tetroxide function as: A. Dehydrating agents B. Clearing agents C. Embedding media D. Fixative solutions Fixative solutions Tissue will remain unfixed if placed in: A. Potassium dichromate B. Sodium borate C. Osmium tetroxide D. Zinc chloride Sodium borate Bouin's 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 Tissue to be stained by the Feulgen reaction 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 Ammonium hydroxide in 70% alcohol 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 Become acidic Microscopic evaluation reveals a 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 Poor fixation To make a 10% formalin solution, how many mL of water should be added to 300 mL of 37-40% formaldehyde solution? A. 1,800 B. 2,500 C. 2,700 D. 3,600 2,700 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 Coagulate nucleoproteins Aldehyde fixatives are used for electron microscopy preparations because they: A. Exert a shrinking effect on tissue B. Render nucleoprotein acidophilic C. Form salt linkages between protein chains D. Coagulate nucleoproteins Preserve cell ultrastructure 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 Will make tissue more receptive to eosin staining 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 Penetrate poorly and cause excessive shrinkage Carnoy solution is recommended for the preservation of: A. Acid-fast bacilli B. Nucleic acids C. Lipids D. Red blood cells nucleic acids Which factor effects light microscopy the least? A. Temperature B. Volume ratio C. Penetration rate D. pH pH 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. Us 7.2 falls below 6 Very bloody cytology smears are often treated with: A. 10% formalin B. Hollande solution C. Clark solution D. Acetone Clark solution Glyoxal is one of the newer fixatives which has the added advantage of: A. Ability to crosslink B. Rapidity of action C. Enhanced staining D. Preservation of erythrocytes Rapidity of action If tissue section was fixed in a solution different from that required for a staining procedure, microscopic sections frequently can be stained anyway if they are: A. Soaked in a soln of lithium carbonate prior to staining B. Revitalized by washing in a soln of sodium bisulfite C. Postfixed in the appropriate fixative prior to staining D. Treated with hydrogen peroxide Postfixed in the appropriate fixative prior to staining 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 frequently used for endocrine tissues 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 37-40% formaldehyde D. mercuric chloride, potassium dichromate, and 37-40% formaldehyde Mercuric chloride, sodium acetate, and 37-40% formaldehyde 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 iodine-sodium thiosulfate What fixative has a mordanting effect on tissue? A. Carnoy solution B. 10% calcium formalin C. Absolute alcohol D. Bouin solution Bouin solution The fixative of choice for the demonstration of a gouty tophus is: A. NBF B. Absolute alcohol C. Bouin solution D. Zenker solution absolute alcohol A good fixative to use 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 Makes tissue more permeable to fluids 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 Running water When fixing tissue for electron microscopy with formaldehyde or glutaraldehyde, the preservation of ultrastructure depends upon all of the following EXCEPT the: A. pH B. Time and temp C. Concentration and purity of the reagent D. Type of tissue Type of tissue Formic acid present in commercial formalin solutions may: A. Facilitate pigment formation B. Precipitate hemosiderin C. Promote staining D. Cause tissue shrinkage facilitate pigment formation Carnoy solution is a combination of which chemicals? A. Absolute alcohol, acetone, and glacial acetic acid B. Cedar wood oil, absolute alcohol, and glacial acetic acid C. Acetone, chloroform, and absolute alcohol D. Chloroform, glacial acetic acid, and absolute alcohol Chloroform, glacial acetic acid, and absolute alcohol Tissue stored for long periods of time in unbuffered formalin or in acetate formalin may show brown, crystalline pigment in stained sections. To remove this pigment prior to staining it is necessary to treat the microscopic section with: A. Saturated alcoholic picric acid B. Alcoholic lithium chloride C. Iodine and sodium thiosulfate D. Potassium permanganate and oxalic acid Saturated alcoholic picric acid For good fixation of tissue with osmium tetroxide for electron microscopy, it is recommended that the tissue segment be no larger than: A. 1 mm cubed B. 2 mm cubed C. 2 cm cubed D. 2 cm cubed 1 mm cubed 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 50% to 70% alcohol The PTAH staining technique would require postfixation, or mordanting, if the tissue were originally fixed in: A. Bouin B. Zenker C. Gendre D. Formalin Formalin Absolute ethanol is a poor choice for the fixation of: A. Glycogen B. Pigments C. Lipids D. Blood smears lipids Which of the following fixatives may give false positive results in some carbohydrate techniques? A. NBF B. Bouin solution C. Gendre solution D. Glutaraldehyde Glutaraldehyde 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 formic acid The rate of fixation varies with the fixative and also with the: A. Time placed in the fixative of choice B. Expected completion time of the report C. Anticipated special stains needed D. Temperature of the fixative solution Temperature of the fixative solution Calcium-formalin fixative is recommended for the BEST preservation and subsequent demonstration of: A. Glycogen B. Phospholipids C. Amyloid D. Estrogen receptors Phospholipids Ultrastructural preservation will be very poor following fixation in: A. Zamboni PAF B. 2% buffered glutaraldehyde C. Osmium tetroxide D. 10% aqueous formalin 10% aqueous formalin 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 15 to 20 times Glyoxal is a/an: A. Aliphatic hydrocarbon B. Aromatic hydrocarbon C. Dialdehyde D. Keytone Dialdehyde 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, and formaldehyde Buffered picric acid and formaldehyde 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, and formaldehyde Buffered picric acid and formaldehyde 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 give poor ultrastructural preservation The preferred fixative when tissue is to be stained for the presence of simple fats is: A. Zenker B. Helly C. Hollande D. NBF NBF Fixation of cytology smears should occur within: A. 1-2 seconds B. 10-15 seconds C. 40-45 seconds D. 1 minute 1-2 seconds 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 interferes with staining The breakdown of tissue due to enzyme activity is called: A. Polymerization B. Putrefaction C. Autolysis D. Osmosis Autolysis When using a nonimmunologic stain for chromaffin granules, it is necessary to fix the tissue in: A. Mercury fixative B. Primary chromate fixative C. Formalin fixative D. Picric acid fixative Primary chromate fixative When liver tissue is fixed with 2% to 3% glutaraldehyde: A. Glycogen is dissolved B. The penetration rate is very rapid C. A chemical reaction occurs with lipids D. The ultrastructure is preserved The ultrastructure is preserved A poor fixative is characterized by: A. The absence of tissue enzymes B. Inactivation of tissue enzymes C. Slow tissue penetration D. The absence of distortion or dissolution Slow tissue penetration Bouin solution contains all of the following EXCEPT: A. Picric acid B. Absolute alcohol C. 37%-40% formaldehyde D. Glacial acetic acid Absolute alcohol Coagulant fixatives: A. Change the sponge-work of proteins into a mesh-like network B. Produce fewer artifacts than non-coagulant fixatives C. Act very slowly to fix tissues D. Leave protein linkages unaffected Change the sponge-work of proteins into a mesh-like network The breakdown of tissue by bacterial action is called: A. Autolysis B. Putrefaction C. Denaturation D. Oxidation putrefaction 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 7.2 to 7.4 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 70% ethanol A fixative component that produces a diffuse brownish black pigment is: A. Picric acid B. Osmium tetroxide C. Mercuric chloride D. Acetic acid Mercuric chloride Ethanol is useful as a fixative because it: A. Crosslinks proteins B. Increases tissue basophilia C. Prevents tissue shrinkage D. Preserves glycogen very well preserves glycogen very well To prevent the formation of formalin pigment in tissues, formalin should be: A. Heated B. Cooled C. Buffered D. Acidified buffered 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 and ruptured cells C. Hardening of the tissue D. No appreciable changes Swollen ruptured cells Which of the following fixatives should be used for specimens that may NOT be processed for several days? A. 10% NBF B. Bouin solution C. Helly solution D. Zenker solution 10% NBF An unknown pigment in a tissue section which bleaches when washed with a saturated solution of picric acid in alcohol is most likely: A. Melanin pigment B. Formalin pigment C. Hemosiderin D. Mercury pigment Formalin pigment We have an expert-written solution to this problem! 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 postfixation washing causes reduction of some chemicals in the solution 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 Monobasic and dibasic phosphates Sections of a breast carcinoma were fixed in a saline solution in the microwave oven. Microscopic examination of 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 68 degrees C C. Use of plastic containers in the microwave D. Presence of carcinoma in the breast tissue Solution temperature exceeding 68 degrees C One characteristic of Zamboni fixative is that it: A. Does not stabilize cellular proteins B. May be used for electron microscopy C. Is easily destroyed by tissue fluids D. Must be followed by osmium tetroxide May be used for electron microscopy 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 used under a chemical hood The BEST fixative for blood smears is: A. Bouin solution B. Carnoy solution C. B-5 solution D. Methanol Methanol Which of the following fixatives is reccomend for use in lipid histochemistry? A. Zenker solution B. Acetone C. Formalin-saline D. Calcium-formalin Calcium-formalin Hollande solution is a modification of which of the following? a. Carnoy b. Zamboni c. Bouin d. Orth Bouin 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 ammonium bromide Tissue fixed in which of the following must be post-treated for mercury pigment? A. B-5 B. Zamboni C. Carnoy D. Orth B-5 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 brain tissue for the diagnosis of rabies 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 physiologic saline at room temperature D. Leaving it in a dry specimen container on the counter with a note to the histologist Wrapping it in saline-moistened gauze and refrigerating it Fixation in Carnoy solution will result in: A. Swelling of the tissue B. Preservation of most cytoplasmic structures C. Superior staining of amyloid with Congo red D. Good preservation of RBC's superior staining of amyloid with Congo red One characteristic of bouin solution is that it: A. Penetrates poorly B. Destroys delicate tissue stains C. Mordants connective tissue stains D. Preserves erythrocytes Mordants connective tissue stains Fixation in Carnoy solution will result in: A. Swelling of the tissue B. Preservation of most cytoplasmic structures C. Superior staining of amyloid with Congo red D. Good preservation of RBC's superior staining of amyloid with Congo red The reccomend fixative for tissue suspected of containing spirochetes is: A. 10% NBF B. Bouin solution C. Zenker solution D. Helly solution 10% NBF Which of the following is frequently added to formalin solutions to help preserve immunoreactivity? A. Glycerin B. Sodium acetate C. Zinc salts D. Chromates Zinc salts Which of the following fixatives is contraindicated when silver stains are to be done for helicobacter pylori? A. Gluteraldehyde B. NBF C. Glyoxal D. Bouin solution Glyoxal the fixation of tissue by physical methods can be accomplished by the use of: A. Microincineration B. Microwaves C. Frozen sections D. Alcohol Microwaves A fixative used for the preservation of some enzymes is: A. Bouin B. B-5 C. Acetone D. Isopropanol acetone Formaldehyde acts as a fixative by: A. Uncovering acid groups B. Coagulating proteins C. Crosslinking proteins D. Rupturing peptide links Crosslinking proteins If 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 Bouin fluid Bouin fixation is contraindicated for Feulgen stains because during fixation: A. Nucleoproteins are precipitated B. Nuclei are excessively hydrolyzed C. Nucleoproteins are crosslinked D. RNA is dissolved nuclei are excessively hydrolyzed When using Bouin fixative, the shrinking effected produced by one component is balanced by the swelling effect of: A. Formalin B. Acetic acid C. Osmium tetroxide D. Potassium dichromate Acetic acid 10% formalin is equivalent to what percent paraformaldehyde solution? A. 40 B. 10 C. 4 D. 1 4 A common reason for adding acetic acid to fixatives is to: A. Coagulate proteins B. Reduce shrinkage C. Preserve carbohydrates D. Change the pH reduce shrinkage To obtain the same nuclear detail characteristic of cytologic preparations, which of the following percentage concentrations of isopropyl alcohol may be substituted for 95% ethyl alcohol? A. 70 B. 80 C. 90 D. 100 80 The presence of acetic acid in fixatives produces: A. Cell shrinkage B. Red cell destruction C. Protein coagulation D. Lipid preservation red cell destruction Which of the following renders fat insoluble for subsequent processing? A. Picric acid B. Osmium tetroxide C. Chloroform D. Formaldehyde osmium tetroxide 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 making the solution neutral Which of the following fixative components produces shrinkage and penetrates poorly? A. Glacial acetic acid B. Mercuric chloride C. Potassium dichromate D. Ethanol Mercuric chloride Which of the following fixatives should be selected when it is desirable to preserve erythrocytes in tissue? A. Clark B. Bouin C. Carnoy D. B-5 B-5 We have an expert-written solution to this problem! When osmium tetroxide is used as a fixative for paraffin embedding it: A. Must be used after a primary fixative B. Should be used on very thin sections C. Should be made hypotonic to tissue D. Must be made basic Should be used on very thin sections 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 Formalin When fat needs to be preserved, the fixative of choice is: A. Formalin B. Zenker C. Carnoy D. Bouin Formalin A tissue section reveals a dark brown microcrystalline pigment which is birefringent. To remove this pigment, the section should be treated with an alcoholic solution saturated with: A. Sodium thiosulfate B. Zamboni solution C. Absolute alcohol D. 10% NBF Absolute alcohol 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. Decreased uptake of eosin D. Hydrolyzed Nucleic acids hydrolyzed nucleic and The primary purpose of fixation is the: A. Preservation of carbohydrates B. Coagulation of lipids C. Removal of tissue fluids D. Stabilization of proteins stabilization of proteins During microtomy, it is noted that most of the tissues are very hard and shrunken. Of the following, the most likely explanation for this problem is that the: A. Infiltrating paraffin is too hot B. Processing reagents need changing C. pH of the fixative was incorrect D. Clearing agent is contaminated with water Infiltrating paraffin is too hot Decalcification of small specimens can be achieved by fixation in: A. NBF B. Zenker solution C. Gluteraldehyde D. Zamboni solution Zenker solution A major disadvantage of aliphatic clearing agents is that they: A. Are incompatible with some mounting media B. Have a very high penetration rate C. Harden tissue excessively D. Are highly toxic are incompatible with some mounting media Which of the following is MOST likely to cause sensitization with prolonged use? A. Cedar wood oil B. Xylene C. Aliphatic hydrocarbons D. Limonene Limonene To speed up the laboratory's processing of all surgical tissues, the temperature of all fixation, dehydration, and clearing steps has been set at 45°C. This will most likely result in: A. Excellent sections of all tissue B. Very soft uterine scrapings C. Microchatter D. Sections that will not stain with eosin Microchatter Limonene functions as a/an: A. Clearing agent only B. Dehydrating agent only C. Universal solvent D. Infiltrating medium clearing agent only One advantage of aliphatic hydrocarbons is that they: A. Have a high tolerance for water B. Are miscible with all mounting media C. Are low in toxicity and sensitization D. Are adaptable to various processing methods are low in toxicity and sensitization A disadvantage of using heat at all stations of the tissue processor is that it will: A. Harden some tissues B. Lengthen processing ti CONTINUED..