Introduction, Histology Techniques

Question 1

Hematoxylin and Eosin staining technique when applied to animal cells stains the nucleus

Answer 1

Blue

Question 2

Hematoxylin and Eosin staining technique when applied to animal cells does not stain the cytoplasm

Answer 2

Blue

Question 3

The most common staining technique is …………….

Answer 3

Hematoxylin and eosin

Question 4

The best method to stain blood cells is ………..

Answer 4

Giemsa

Question 5

The following are common fixing agents except:
a)Xylene
b)Potassium dichromate
c)Formaldehyde
d)Chronic acid
e)Chlorofoam

Answer 5

Xylene

Question 6

The sequence of slide production is as follows;

Answer 6

• Fixation
• Dehydration
• Clearing
• Wax impregnation
• Embedding
• Sectioning
• Clearing/Dewaxing and Rehydrating
• Staining
• Mounting

Question 7

Osmic acid is used for staining the ………… part of a nerve fibre

Answer 7

Myelin sheath

Question 8

Examples of fixatives include;

Answer 8

buffered formalin, Bouin’s fluid, refrigeration(fresh frozen tissues), heat, salt etc

Question 9

Fixative/Tissue vol ratio = ?

Answer 9

3:1

Question 10

Differentiate between autolysis and putrefaction

Answer 10

Autolysis/self breakdown refers to degeneration caused by enzymatic action while Putrefaction/Decay is caused by bacterial action

Question 11

What must be done to prevent autolysis and putrefaction?

Answer 11

Tissues are immersed in fixatives

Question 12

What is used in tissue dehydration?

Answer 12

Alcohol, ascending grades

Question 13

What is the effect of improper dehydration?

Answer 13

bubbles in tissue sections
Distortion due to sudden shrink

Question 14

What is meant by clearing in tissue processing?

Answer 14

Removal of alcohol

Question 15

Name some clearing agents.

Answer 15

xylene, benzene, toluene, chloroform

Question 16

Wax impregnating refers to ………..?

Answer 16

Filling of all spaces within tissue with wax for solid fine cut

Question 17

Embedding refers to?

Answer 17

Embedding in paraffin wax to obtain tissue blocks
This brings tissue to a hard solid medium to maintain tissue architecture on sectioning

Question 18

Sectioning means ………….?

Answer 18

Using microtome, thin sections are cut (usually 4 μm but can be 2–10 μm)
Resultant ribbons are floated in warm water bath (typically 5–9 °C below m.p. of the wax)

Question 19

……….. is used in clearing

Answer 19

Xylene

Question 20

How is rehydration achieved?

Answer 20

Treating the tissue with descending grades of alcohol; from absolute down to 50% and then to water

Question 21

Haemotoxylin is a basic dye that stains ………….

Answer 21

The acidic nucleus

Question 22

Eosin is an acidic dye that stains …………

Answer 22

The basic cytoplasm

Question 23

complex CHOs are stained deep red/magenta by ……..

Answer 23

Periodic acid schiff (PAS)

Question 24

Van Gieson stains the cytoplasm and RBCs …………

Answer 24

Yellow

Question 25

Osmium tetroxide stains lipids ………..

Answer 25

Black

Question 26

………… is a common mountant?

Answer 26

DPX