Deck 1: Fixation

Question 1

Which of the following best describes fixation?

A)A procedure adopted to kill, harden and preserve the tissue for microscopic study by the use of substances like xylene.
B)A procedure adopted to kill, harden and preserve the tissue for microscopic study by the use of substances like mercuric chloride.
C)The procedure in which the ionic materials are removed from the tissue.
D)The process of removing intracellular and extracellular H₂O.

Answer 1

A procedure adopted to kill, harden and preserve the tissue for microscopic study by the use of substances like mercuric chloride.

Question 2

What are the characteristics of a good fixative?

A)It must inhibit bacterial decomposition and autolysis.
B)It must permit rapid and even penetration of tissues.
C)Both A and B
D)None of the above

Answer 2

Both A and B

Question 3

Which of the following is not an example of a nuclear fixative?

A)Flemming's fluid
B)Newcomer's fluid
C)Heidenhain's Susa
D)Orth's fluid

Answer 3

Orth's fluid

Question 4

Which of the following is the advantage of glutaraldehyde over formaldehyde as a fixative?

A)It is cheap and readily available.
B)It produces less tissue shrinkage.
C)It is compatible with many stains.
D)All of the above.

Question 5

What is the ideal preparation or concentration of formaldehyde?

A)15% solution
B)3% solution
C)8% solution
D)10% solution

Question 6

What is the usual fixation time when using 10% formaldehyde?

A)3 hours
B)12 hours
C)24 hours
D)72 hours

Question 7

What is the formula needed to prepare a 10% formol-saline?

A)100ml of 40% formaldehyde, 9g of NaCl, and 900ml of distilled water
B)100ml of 10% formaldehyde, 10g of NaCl, and 1000ml of distilled water
C)100ml of 5% formaldehyde, 11g of NaCl, and 1200ml of distilled water
D)100ml of 20% formaldehyde, 5g of NaCl, and 1500ml of distilled water

Question 8

What is the ideal concentration of ethyl alcohol used when fixing blood, tissue films and smears?

A)70% ethyl alcohol
B)75% ethyl alcohol
C)85% ethyl alcohol
D)95% ethyl alcohol

Question 9

This is the fixative that is considered to be the most rapid fixative.

A)Newcomer's fluid
B)Flemming's solution
C)Carnoy's Fluid
D)Formalin

Question 10

Which of the following is used as dehydrating agent and as a fixative at the same time?

A)Acetone
B)Mercuric Chloride
C)Acetic acid
D)Both A and B

Question 11

What substance is added to formaldehyde in order to remove the precipitate produced by prolonged storage?

A)Acetone
B)Acetic acid
C)Methanol
D)Distilled water

Question 12

It is used in fixing brain tissues for the diagnosis of rabies.

A)Heat fixation
B)Alcohol
C)Acetone
D)Osmic acid

Question 13

Which of the following retards fixation of tissues?

A)Smaller and thinner tissues
B)Agitation
C)Moderate heat at about 37-56 degree Celsius.
D)Presence of fat

Question 14

On which of the following specimens do you primarily use Sudan stains?

A)nerve tissue
B)fat
C)muscle fibers
D)bone

Question 15

Heat fixation should be used on the following except for:

A)Gram stain
B)Capsular staining
C)Endospore staining
D)Acid Fast stain

Question 16

Which of the following is not a purpose of fixation?

A)Acts to disable proteolytic enzymes that digest or damage the sample
B)Protects the sample from extrinsic damage
C)Prevents autolysis or putrefaction
D)Decreases the mechanical strength or stability of cells and tissues

Question 17

Which of the following statements does not accurately describe formaldehyde?

A)It penetrates the tissues rapidly
B)Formaldehyde fixes tissue specimens at a rapid rate of about 1mm per hour.
C)It is an ideal fixative for nucleic acids
D)It is one of the most commonly used aldehyde fixative

Question 18

Which of the following properties of Mercuric chloride makes it restricted for use?

A)Toxic
B)Corrosive
C)Dangerous to the environment
D)All of the above

Question 19

Which of the following properties of microwave fixation makes it unsuitable for use in large specimens?

A)Microwaves can damage fine tissue structures
B)Microwave fixation is ideally used for 10-12mm tissue blocks
C)Using microwaves increases the rate of autolysis
D)Microwave fixation inadequately heats the core of a large specimen without it significantly overheating the exterior portion

Question 20

Which among the following is not a property of acetic acid?

A)It causes the shrinkage of collagen
B)It is an agent used for denaturation
C)It does not generally fix proteins
D)It is a precipitating fixative

Question 21

The following are the preferred fixatives to be used on lipids except:

A)Frozen sections
B)Glutaraldehyde
C)Neutral buffered formalin
D)Osmium tetroxide

Question 22

Which of the following statements is true about heat fixation?

A)It preserves overall morphology and preserves the internal structures
B)It does not preserve overall morphology, but it preserves internal structures
C)It does not preserve both overall morphology and the internal structures
D)It preserves overall morphology, but it does not preserve the internal structures

Question 23

One disadvantage of using perfusion as a fixation process is:

A)It is a costly process
B)It makes the subject paralyzed
C)The volume of fixative used is smaller
D)The tissue does not die until it is fixed

Question 24

Which statement best describes the rule of thumb for immersing a specimen in a fixative?

A)The volume of the fixative must be 5 times greater than the volume of the specimen
B)The volume of the fixative must be equal to the volume of the specimen
C)The volume of the fixative must be 20 times the volume of the specimen
D)The volume of the fixative should be slightly more than the volume of the specimen

Question 25

This process of fixation preserves structures in a state that is chemically and structurally as close to the living tissue as possible.

A)Heat fixation
B)Chemical fixation
C)Perfusion
D)Immersion

Question 26

Which of the following fixatives do not belong to the group of oxidizing agents?

A)Potassium dichromate
B)Mercuric chloride
C)Chromic acid
D)Osmium tetroxide

Question 27

What are the advantages of utilizing frozen sections?

A)Lack of morphological detail
B)Much faster than other forms of fixation
C)Not exposed to organic solvents
D)Both B and C

Question 28

The following are the factors that would affect the process of fixation, except:

A)Volume of the fixative used
B)Size of the specimen
C)Pressure on the specimen
D)Temperature

Question 29

Which among the following statements is not true about penetration?

A)The rate of penetration is always affected by heat.
B)The penetration of fixatives can be improved by opening up a tissue sample.
C)The concentration of the fixative always affects penetration.
D)The presence of intestinal contents can inhibit the penetration of fixatives.

Question 30

Which among the following is a physical method of fixation?

A)Microwave fixation
B)Cryo-preservation
C)Immersion fixation
D)Both A and B

Question 31

Why is glutaraldehyde the preferred fixative for specimens in electron microscopy?

A)Glutaraldehyde is much easier to obtain than formaldehyde.
B)It excels at preserving the detailed structures of the cells and tissues
C)Tissues fixed with glutaraldehyde stain well with dyes.
D)Glutaraldehyde does not change the solubility of the fixed tissue.

Question 32

Among the statements about antigen preservation, which among the following is not correct?

A)All reactions with formaldehyde-fixed specimens can be reversed.
B)The quality of antigen preservation varies with respect to the type of fixative used.
C)The ability to preserve antigens is important when choosing a fixative to use.
D)Some fixation reactions are reversible in aldehyde-fixed specimens.

Question 33

Which of the following statements is true about temperature being a factor in fixation?

A)Fixation is usually done at room temperature
B)As temperature increases, the speed of fixation decreases
C)"Cooking" the specimen is accepted in fixation.
D)As the temperature increases, the fixation speed remains the same.

Question 34

What is the suitable pH for fixation?

A)pH 2 to 3
B)pH 4 to 6
C)pH 6 to 8
D)pH 7 to 9

Question 35

What type of fixative gives the best result in fixation?

A)Slightly hypertonic fixative
B)Hypertonic fixative
C)Hypotonic fixative
D)Isotonic fixative

Question 36

What is the preferred duration of fixation when using buffered formalin?

A)1 to 2 hours
B)2 to 6 hours
C)48 hours
D)72 hours

Question 37

As a histotechnician, one must know the basics of fixation before it occurs. One of the basic principles to remember is the ideal size of the tissue. Therefore, what is the ideal size of the tissue before fixing it?

A)0)5 cm²
B)1 cm²
C)2 cm²
D)3 cm²

Question 38

Aside from considering the adequate size of the tissue sample, the histotechnician must also take note of the sample's thickness. Which among the following is the ideal thickness of the tissue sample to attain quality fixation?

A)1 mm
B)2 mm
C)3 mm
D)4 mm

Question 39

Which of the following tissue samples is fixed first before sectioning or grossing?

A)Heart
B)Brain
C)Liver
D)Pancreas

Question 40

If a histotechnician receives a sample that contains glycogen, what fixative of choice is suitable for the demonstration and preservation of glycogen?

A)Neutral buffered formol saline
B)Rossman's fluid
C)Carnoy's fluid
D)Heidenhain's fluid

Question 41

What type of fixative is commonly used for amino acid histochemistry?

A)Formaldehyde vapor
B)Alcoholic fixative
C)Baker's formol calcium
D)Acetone

Question 42

This is a very basic fixative made up of 40% saturated formaldehyde attenuated to 10% with 10% NaCl. What is this type of fixative?

A)Gendre's fixative
B)Formal-Sublimate
C)Glutaraldehyde
D)10% formol-Saline

Question 43

What is this type of metallic fixative that produces black precipitates?

A)Mercuric chloride
B)Chromate fixative
C)Lead fixative
D)Heidenhain's Susa

Question 44

What type of Mercuric chloride fixative is added with glacial acetic acid to avoid dark precipitate development?

A)Zenker's Fluid
B)B-5 fixative
C)Muller's fluid
D)Heidenhain's Susa

Question 45

This type of picric acid fixative is recommended for the preservation of embryos and pituitary biopsies.

A)Bouin's solution
B)Brasil's Alcoholic picroformol
C)Glacial acetic acid
D)Carnoy's fluid

Question 46

It is a type of fixative that is ideal for small tissue fragments and must be used in higher concentrations to better fix the sample. What is this type of fixative?

A)Alcohol
B)Acids
C)Aldehydes
D)Metallic fixatives

Question 47

This type of fixation is usually done using thermal coagulation, which is suitable for frozen tissue sections and for the preparation of bacteriological smears?

A)Absolute alcohol fixation
B)Metallic fixation
C)Heat fixation
D)Acid fixation

Question 48

This fixative is preferred for the preservation of chromosomes, lymph glands and urgent biopsies, as well as to preserve brain tissue for the identification of rabies.

A)Carnoy's Fluid
B)100% Methyl alcohol
C)Bouin's Solution
D)Muller's Fluid

Question 49

Among the choices below, which of the following fixatives is preferred for the preservation of mucopolysaccharides and nuclear proteins?

A)Carnoy's Fluid
B)100% Methyl Alcohol
C)Newcomer's Fluid
D)Bouin's Solution

Question 50

This fixative is made up of chromic and osmic acid, suggested for cytoplasmic structures particularly the mitochondria. Which of the following choices below best describes the statement above?

A)Flemming's solution
B)Trichloroacetic acid
C)Bouin's Solution
D)Muller's Fluid

Question 51

This type of fixative is preferred for the diagnosis of early degenerative processes and tissue necrosis.

A)Muller's Fluid
B)Orth's Fluid
C)Heidenhain's Susa
D)Zenker-formol

Question 52

This is type of fixative is usually incorporated with other fixatives to form a compound solution. This hardens at 17 degree Celsius. What type of fixative is this?

A)Alcohol
B)Glacial acetic acid
C)Carnoy's Fluid
D)Muller's Solution

Question 53

This type of fixative is ideal for the diagnosis of water diffusible enzymes especially phosphatases and lipase but produces unavoidable shrinkage and deformation.

A)Alcohol
B)Acetone
C)Heat
D)Acid

Question 54

This is also the fixative of choice for the preservation of brain tissue for the diagnosis of rabies. Which among the choices below is described by the statement above?

A)Heat fixation
B)Alcohol
C)10% formol-saline
D)Acetone

Question 55

Which of the following is the fixative of choice for fixing brain tissue?

A)Acetone
B)Alcohol
C)Carnoy's Fluid
D)Both A and C

Question 56

A histotechnician receives a sample of bone marrow for biopsy. What fixative of choice is suitable for bone marrow preservation?

A)Alcohol
B)B-5 fixative
C)Carnoy's fluid
D)Orth's fluid

Question 57

It is an excellent fixative that is chiefly recommended for tumor biopsies especially of the skin.

A)Heidenhain's Susa Solution
B)Helly solution
C)B-5 Fixative
D)Zenker's Fluid

Question 58

All of the following choices below are the disadvantages of the formalin fixative, except:

A)Dermatitis on prolonged contact.
B)It may produce considerable shrinkage of the tissue.
C)Prolonged fixation may produce bleaching of the specimen and loss of natural tissue colors.
D)It evaporates quickly.

Question 59

All of the following choices below are fixatives of choice for electron microscopy, except:

A)100% Methanol
B)Osmium Tetroxide
C)Glutaraldehyde
D)Paraformaldehyde

Question 60

It is the fixative of choice used to preserve touch preparations and for staining procedures of Wright- Giemsa.

A)Acetone
B)Formalin
C)Isopropyl alcohol
D)Osmic acid

Question 61

It is the fixative of choice to better exhibit Rickettsiae and other bacteria.

A)Muller's Fluid
B)Orth's Fluid
C)Heidenhain's Susa
D)Zenker-formol

Question 62

Allan understands that this metallic fixative has been discovered to react with viruses.

A)Potassium dichromate
B)Osmium tetroxide
C)Chromic acid
D)Mercuric chloride

Question 63

John Daniel knows that concentrated solutions of formaldehyde must never be neutralized as this will:

A)Cause increased bleaching of the tissues
B)Increase the rate of decomposition of formaldehyde
C)Stimulate violent chemical explosions
D)Cause formalin to become ineffective as a fixative