Clearing Flashcards
It can clear 70% alc without excessive tissue shrinkage and hardening
Aniline oil
True or false:
Viscosity has no effect in the speed of penetration of the clearing agent
False
Most common dehydrating agent
Xylene/ xylol
True or false:
good clearing agent should dissolve out aniline dye
False. It should not dissolve aniline dye
Cedarwood is hard to remove from tissues in paraffin bath making wax impregnation process very slow. What could be done to avoid this?
Transfer the specimen from oil to benzene for half hour before finally placing the tissue in wax
True or false:
A good clearing agent should be miscible with and easily removed by melted paraffin wax and/ or mounting medium
True
Clearing time of xylene
30mins to 1hr
The following are true about xylene except?
A. It is the most rapid and also cheap
B. Suitable for nervous tissue and lymph nodes
C. It does not dissolve celloidin and can be used for celloidin sections
D. It becomes milky when an incompletely dehydrated tissue is immersed in it
B. It is not Suitable for nervous tissue and lymph nodes because it causes considerable hardening and shrinkage of tissues
Substitute for xylene
Toluene
Clearing time of toluene
1-2hrs
Excessive exposure to benzene may be extremely toxic and cause what?
Aplastic anemia
Clearing agent that is used for thick blocks (1 in thickness)
Chloroform
Clearing time of chloroform
6-24hrs
A clearing agent that is rapid acting and is recommended for urgent biopsies
Benzene
The process whereby dehydrating agent is removed from the tissue
Clearing/ de-alcoholization
Tissue tends to float in chloroform. What should be done to avoid this?
Wrap the tissue with absorbent cotton gauze
Recommended for clearing embryos, insects, and very delicate specimens
Aniline oil
Especially recommended for central nervous tissue
Cedarwood oil
True or false:
Tissues placed in chloroform do not become transparent
True
True or false:
Chloroform is recommended for tough tissues, nervous tissues, lymph nodes and embryos
True
True or false:
Clearing fluids with low boiling point are generally more readily replace by melted paraffin wax
True
True or false:
If tissue is left for 24hrs in toluene, the tissue becomes excessively hard and brittle
False. It does not
True or false: clearing agent must be miscible with paraffin wax in order to facilitate penetration or this embedding medium
True