BOC Fixative

An example of an additive fixative 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 is 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

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
B. Bouin
C. Gendre
D. Hollande

Hollande

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 temp
D. Osmolality of the fixation solution

Control of the temp

To adequately remove the calcium from a specimen containing areas of micro-calcification, the tissue could be fixed in:
A. Hollande
B. NBF
C. B-5
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
D. Zamboni

Absolute alcohol

Improper preservation of tissue 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, ad 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

Which of the following fixatives contains copper acetate?
A. Hollande
B. Bouin
C. Gendre
D. Zamboni

Hollande

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 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 lab 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. Are readily available
B. Visibly stain tissue
C. Preserve cell ultrastructure
D. Coagulate tissue lipids

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

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
C. Gendre
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

Carnoy solution is recommended for the preservation of:
A. Acid-fast bacilli
B. Nucleic acids
C. Lipids
D. Red blood cells

Nucleic acids

Which of the following factors affects fixation for light microscopy the lease?
A. Temp
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. Is 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

Which of the following fixatives has a mordanting effect on tissue?
A. Carnoy solution
B. 10% calcium formalin
C. Absolute alcohol
D. Bouin solution

Bouin solution

Tissue should be placed in a fixative solution immediately after removal from the body to:
A. Prevent decomposition due to enzymatic activity
B. Permit the dehydrant to function properly
C. Inhibit crosslinking of tissue proteins
D. Stabilize tissue carbohydrates

Prevent decomposition due to enzymatic activity

Calcium-formalin fixative is recommended for BEST preservation and subsequent demonstration of:
A. Glycogen
B. Phospholipids
C. Amyloid
D. Estrogen receptors

Phospholipids

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

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

Glyoxal is a/an:
A. Aliphatic hydrocarbon
B. Aromatic hydrocarbon
C. Dialdehyde
D. Keytone

Dialdehyde

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

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

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

The fixative of choice for the demonstration of gouty tophus is:
A. NBF
B. Absolute alcohol
C. Bouin solution
D. Zenker solution

Absolute alcohol

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

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 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

Chloroform, glacial acetic acid, and absolute alcohol

When using a nonimmunologic stain for chromaffin granules, it is necessary to fix the tissue in a:
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 shrinking or swelling of tissue
B. Inactivation of tissue enzymes
C. Slow tissue penetration
D. The absence of distortion of dissolution

Slow tissue penetration

Bouin solution contains all of the following EXCEPT:
A. Picric acid
B. Absolute alcohol
C. 27-40% 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

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

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

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

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

A biopsy that was placed in water by mistake is submitted to the lab. This mistake most likely will cause:
A. Mushy sections
B. Swollen and ruptured cells
C. Hardening of the tissue
D. No appreciable changes

Swollen and ruptured cells

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

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

Formalin pigment

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

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

The BEST fixative for blood smears is:
A. Bouin solution
B. Carnoy solution
C. B-5 solution
D. Methanol

Methanol

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

Which of the following fixatives is recommended for use in lipid histochemistry?
A. Zenker solution
B. Acetone
C. Formalin-saline
D. Calcium-formalin

Calcium-formalin

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

Hollande solution is a modification of which of the following fixatives?
A. Helly
B. Orth
C. Carnoy
D. Bouin

Bouin

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

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 temp
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

One characteristic of Bouin solution is that it:
A. Penetrates poorly
B. Destroys delicate structures
C. Mordants connective tissue stains
D. Preserves erythrocytes

Mordants connective tissue stains

The fixation of tissue by physical methods can be accomplished by the use of:
A. Microincineration
B. Microwaves
C. Frozen sections
D. Alcohol

Microwaves

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 recommended fixative for tissue suspected of containing spirochetes is:
A. 10% NFB
B. Bouin
C. Zenker
D. Helly

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 H. pylori?
A. Glutaraldehyde
B. NBF
C. Glyoxal
D. Bouin

Glyoxal

A fixative used for the preservation of some enzymes is:
A. Bouin
B. B-5
C. Acetone
D. Isopropanol

Acetone

A common reason for adding acetic acid to fixatives is to:
A. Coagulate proteins
B. Reduce shrinkage
C. Preserve carbohydrates
D. Change pH

Reduce shrinkage

Formaldehyde acts as a fixative by:
A. Uncovering acid groups
B. Coagulating proteins
C. Crosslinking proteins
D. Rupturing peptide linkages

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
C. Absolute alcohol
D. Bouin

Bouin

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 effect produced by one component is balanced by the swelling effect of:
A. Formalin
B. Acetic acid
C. Osmium tetroxide
D. Potassium dichromate

Acetic acid