Introduction, Histology Techniques Flashcards
Hematoxylin and Eosin staining technique when applied to animal cells stains the nucleus
Blue
Hematoxylin and Eosin staining technique when applied to animal cells does not stain the cytoplasm
Blue
The most common staining technique is …………….
Hematoxylin and eosin
The best method to stain blood cells is ………..
Giemsa
The following are common fixing agents except:
a)Xylene
b)Potassium dichromate
c)Formaldehyde
d)Chronic acid
e)Chlorofoam
Xylene
The sequence of slide production is as follows;
• Fixation
• Dehydration
• Clearing
• Wax impregnation
• Embedding
• Sectioning
• Clearing/Dewaxing and Rehydrating
• Staining
• Mounting
Osmic acid is used for staining the ………… part of a nerve fibre
Myelin sheath
Examples of fixatives include;
buffered formalin, Bouin’s fluid, refrigeration(fresh frozen tissues), heat, salt etc
Fixative/Tissue vol ratio = ?
3:1
Differentiate between autolysis and putrefaction
Autolysis/self breakdown refers to degeneration caused by enzymatic action while Putrefaction/Decay is caused by bacterial action
What must be done to prevent autolysis and putrefaction?
Tissues are immersed in fixatives
What is used in tissue dehydration?
Alcohol, ascending grades
What is the effect of improper dehydration?
bubbles in tissue sections
Distortion due to sudden shrink
What is meant by clearing in tissue processing?
Removal of alcohol
Name some clearing agents.
xylene, benzene, toluene, chloroform
Wax impregnating refers to ………..?
Filling of all spaces within tissue with wax for solid fine cut
Embedding refers to?
Embedding in paraffin wax to obtain tissue blocks
This brings tissue to a hard solid medium to maintain tissue architecture on sectioning
Sectioning means ………….?
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)
……….. is used in clearing
Xylene
How is rehydration achieved?
Treating the tissue with descending grades of alcohol; from absolute down to 50% and then to water
Haemotoxylin is a basic dye that stains ………….
The acidic nucleus
Eosin is an acidic dye that stains …………
The basic cytoplasm
complex CHOs are stained deep red/magenta by ……..
Periodic acid schiff (PAS)
Van Gieson stains the cytoplasm and RBCs …………
Yellow
Osmium tetroxide stains lipids ………..
Black
………… is a common mountant?
DPX
