MTAP 2: Q1

B

Fixation for Electron Microscopy using paraformaldehyde at

a. RT

b. 4 degC

c. 40 degC

d. Both A and B are correct

e. None of these

B

Formalin pigments that may be produced during fixation under acid conditions can be eliminated or reduced by fixation using

a. Non-buffered formalin

b. Phenol-formalin

c. Alcoholic formalin

d. All of these

e. None of these

D

Fixatives containing _____ can be used effectively for preservation of lipids in cryostat sections.

a. Mercuric chloride

b. Picric acid

c. Potassium dichromate

d. A and C

e. All of these

C

Fixative type generally recommended for glycogen fixation

a. Mercuric chloride-based

b. Aldehyde-based

c. Alcohol-based

d. All of these

e. None of these

A

All of the following processes will ensure adequate tissue fixation except:

a. Lung specimen inflated with fixative

b. Gauze was inserted in tubular organ like umbilical cord

c. GIT specimens incised prior to fixation

d. B and C

e. None of these

E

In fixation, the fixative to be used must have a buffering capacity to prevent excessive acidity because acidity favors formation of formalin-heme pigment that appears as black deposits in tissues. What buffering agent may be used for this purpose?

a. Phosphate

b. Bicarbonate

c. Cacodylate

d. A and B only

e. All of these

A

Commercial formalin is buffered using ____ at a pH of 7. Use choices in #6

a. Phosphate

b. Bicarbonate

c. Cacodylate

d. A and B only

e. All of these

D

Best results in fixation are usually obtained using slightly hypertonic solutions with osmolality of ____

a. 340 mOsm

b. 500 mOsm

c. 250 mOsm

d. 400 mOsm 

e. None of these

A

Concentration of glutaraldehyde found to be an ideal concentration of EM is 

a. 3%

b. 10%

c. 0.25%

d. 5%

e. None of these

C

Formalin with “post chroming” may be used for 

a. Histochemical fixation

b. Nuclear fixation

c. Cytoplasmic fixation

d. Both B and C

e. none of these

A

Which of the following tissue type will require immersion in 4% aqueous phenol solution for 1-3 days following fixation

1. Fibroids

2. Human brain

3. Cervix

4. Spleen 

a. 1 and 3

b. 2 and 4

c. 1, 2, and 3

d. 1, 2, 3, & 4 

e. None of these

B

True of microwave technique except

a. Suited for rapid fixation of routine surgical specimens

b. Can penetrate tissues with a thickness of 20 mm

c. It is a “non-chemical” technique

d. All of these

A

Prolonged fixation with formalin may produce all of the following except:

a. Bleaching of the specimen

b. Glycogen loss

c. Dispersal of fat from tissue into the fluid

d. Abundant brown pigment granules

e. None of these

B

Following fixation, natural tissue colors may be restored by immersing tissues in 

a. Acetone

b. 70% alcohol

c. Saturated alcoholic picric acid

d. All of these

e. None 

B

An alternative to mercuric chloride formulation that when used can give improved results with immunohistochemistry is 

a. Alcoholic formalin

b. Zinc formalin

c. Rossmann’s solution

d. B and C

e. None

A

Which of the following “precipitating” fixatives can be used for histochemistry especially for enzyme studies as it preserves nucleoproteins and nucleic acid

a. 70-100% ethyl alcohol

b. 95% IPA

c. Carnoy’s

d. A and B only

e. All of these

B

The alcohol-based fixative used for “touch preparations”. Use choices in #16

a. 70-100% ethyl alcohol

b. 95% IPA

c. Carnoy’s

d. A and B only

e. All of these

A

All of the following are components of Carnoy’s fluid, which one is not?

a. Acetone

b. Chloroform

c. Glacial acetic acid

d. Absolute alcohol

e. None of these

E

The following are “precipitating”/alcoholic fixatives

1. Clarke’s

2. Gendre’s

3. Newcomer’s 

   a. 1 only

   b. 1 & 3

   c. 2 & 

   d. 1 & 2

   e. All of these

C

Which of the following is recommended for fixing GIT as well as endocrine tissues?

a. Clarke’s

b. Gendre’s

c. Hollande’s 

d. Flemings

e. None of these

B

True of acetone

a. Often used alone without dilution

b. Can fix specimen at 0-4 deg C

c. For fixation of cryostat sections

d. B and C

e. All of these

A

Which of the following fixing agents has a softening effect on dense fibrous tissues?

a. TCA

b. Glacial acetic acid

c. Lead fixative

d. Acetone

e. None of these

D

From the choices #22, which fixing agent is recommended for the study of water diffusible enzymes?

a. TCA

b. Glacial acetic acid

c. Lead fixative

d. Acetone

e. None of these

C

Fixation of connective tissue mucins can be accomplished using which of the following?

a. TCA

b. Glacial acetic acid

c. Lead fixative

d. Acetone

e. None of these

B

Which of the following can be an excellent fixative for chromosomes?

a. Clarke’s

b. Fleming solutions

c. Hollande’s

d. Brasil’s 

e. All of these

A

In dealcoholization process what is the ideal amount of the agent?

a. Not less than 10X specimen volume

b. More than 50x specimen volume

c. Tissue volume equal to the amount of fixing agent

d. None of these

D

A good clearing agent must be one that is miscible with 

a. Paraffin wax

b. Canada balsam

c. Alcohol

d. All of these 

e. A and C only

D

Aplastic anemia is likely to develop in those with prolonged exposure to 

a. Chloroform

b. Xylene

c. Alcohol

d. None of these

B

A xylene substitute with a tendency to get solidified at a lower temperature

a. Chlorinated hydrocarbons

b. Coconut oil 

c. Terpenes

d. All of these

e. None of these

B

Clearing of embryo specimens may be carried out using

a. Clove oil

b. Carbon tetrachloride

c. Cedarwood oil

d. Dioxane

e. All of these

f. None of these

D

The use of chloroform can clear which of the following specimen types. Use lettered choices in 11.

1. Embryos

2. Lymph nodes

3. Skin 

4. Decalcified tissues

a. 1 and 3

b. 2 and 4

c. 1, 2, and 3

d. 1, 2, 3, & 4 

e. None of these

C

Colloid containing tissues can be fixed using which of the following?

a. Orth’s

b. Bouins’s 

c. Regaud’s

d. Rossman’s

e. None of these

C

Choose the correct pair, fixing agent, and classification as to the basic component

a. Bouin’s - aldehyde

b. Rossman’s - mercuric chloride

c. Hollande’s - picric acid

d. Lilies B5 - alcohol

e. None of these

B

Can be used extensively for neurological studies

a. Heidenhain’s susa

b. Osmium tetroxide

c. Potassium dichromate

d. All of these

e. None of these

E

Because of its ability to coagulate mucus, what agent may be used for the fixation of sputum samples?

a. Formol-acetic alcohol

b. Zenker’s 

c. Heidenhain’s susa

d. Helly’s

e. None of these

B

Tissue fixatives with a pH of 4.6 or less (use lettered choices of #11)

1. Regaud’s

2. Bouin’s 

3. Formalin with post-chroming

4. Carnoy’s 

a. 1 and 3

b. 2 and 4

c. 1, 2, and 3

d. 1, 2, 3, & 4 

e. None of these

C

Use of tap water in washing out to remove excess agent following fixation may be necessary for tissues fixed using

a. Picric acid fixatives

b. Mercuric fixatives

c. Chromate fixative

d. All of these

e. None of these

A

In the dehydration process, the concentration of ethanol bath must be

a. Increasing

b. The same all throughout the process

c. Decreasing 

d. None of these

B

What fixing agent is commonly used for amino acid histochemistry?

a. Formol corrosive

b. Neutral buffered formal saline

c. Paraformaldehyde

d. Acrolein

B

An aldehyde fixative introduced as mixture with glutaraldehyde or formaldehyde

a. Glyoxal

b. Acrolein

c. Paraformaldehyde

d. None of these

B

The clearing agent that can become milky on prolonged storage is

a. Xylene

b. Cedarwood oil

c. Clove oil

d. Aniline oil

e. Chloroform

A

The clearing agent that can become milky due to incomplete dehydration. Use choices in #41

a. Xylene

b. Cedarwood oil

c. Clove oil

d. Aniline oil

e. Chloroform

B

Clearing agent recommended for specimens like smooth muscles of the skin. Use choices in #41

a. Xylene

b. Cedarwood oil

c. Clove oil

d. Aniline oil

e. Chloroform

A

Which of the following have properties very similar to chloroform?

a. Carbon tetrachloride

b. Clove oil

c. Cedarwood oil

d. Toluene

B

From the choices in #44, which agent that when used will make wax impregnation slow and difficult?

a. Carbon tetrachloride

b. Clove oil

c. Cedarwood oil

d. Toluene

C

True of tetrahydrofuran except:

a. Odorous and therefore room must be well ventilated

b. Non-toxic

c. Does not easily evaporate

d. Fast-acting

C

Ethylene glycol mono-ethyl ether is also known as

a. Dioxane

b. Diethylene dioxide

c. Cellosolve

d. Triethyl phosphate

e. None of these

C

Weisenberger and Graupner are ____ methods of dehydration

a. Alcohol

b. Acetone

c. Dioxane

d. Cellosolve

B

The temperature that will hasten dehydration time and is therefore recommended for urgent examinations

a. RT

b. 37 degC

c. 4 deg

d. None of these

C

True of an ideal dehydrating agent except

a. Should not evaporate easily

b. Should not remove stains

c. Should not dehydrate fatty tissues

d. None of these