Dehydration And Clearing Flashcards
Designed to remove all extractable water from the tissue, it also allows visualization microscopically
Dehydration
Removal of intercellular and extracellular water from the tissue and increasing concentration of alcohol
Dehydration
Routine starts with ______
70% ethyl alcohol
Embryonic tissues starts with ___________
30% ethyl alcohol or ethanol
Ratio of dehydrating agent and tissue
10:1
Qualities of an ideal dehydrating solution
Rapid acting
Should not evaporate fast
Non toxic
Not fire hazard
These are capable of evaporation or highly volatile due to readily combination with water
Dehydrating agent
A type of dehydrating agent that is both fixative and dehydrating
- best, fastest, mixes with water and penetrates easily, not poisonous, cheap
Ethyl (ethanol)
A type of dehydrating agent that is toxic and used for blood films
Methyl (methanol)
A type of dehydrating agent that is slow and used for plant and animal microtechniques
Butyl (butanol)
Prolonged storage in 70% alcohol: ________
Macerates tissue
Directly placed in high grade alcohol:___________
Shrinkage and hardening
Other dehydrating agents that is readily available, cheap and rapid acting
- can cause tissue shrinkage
Acetone
Other type of dehydrating agent that is excellent dehydrating and clearing agent, can cause less tissue shrinkage
- ribbons poorly and expensive
Dioxane (diethyl dioxide)
Other type of dehydrating agent that is rarely used in terms of dehydration because it has more disadvantage that advantage
Cellosolve
It dehydrates rapidly, storage without producing hardening or distortion
Cellosolve
Other type of dehydrating agent that is used to dehydrate sections and smears following certain stains
Triethyl phosphate
Other type of dehydrating agent that is non toxic and has offensive odor
Tetrahydrofuran
4% phenol added to 95% ethanol
Softens hard tissues
For hard tissues
Immerse in glycerol/alcohol mixture /molliflex
A process in which we try to remove excess alcohol and water
Clearing
Removal of dehydrating solutions, making the tissue components receptive to the infiltrating medium
Clearing
Improve refractive index of the tissue
Clearing
It is the ability of the tissue to be closely monitored or seen if it is focused under hpo or lpo
Refractive index
Clearing is also known as
Dealcoholization
Characteristics of good clearing agents
Miscible with alcohol and paraffin/ mounting medium
Should not produce excessive tissue shrinkage
Should not evaporate quickly
Should make tissues transparent
A type of clearing agent that is highly utilized, most common, colorless and most rapid
Xylene/ Xylol
It is not for nervous system and lymph nodes
Xylene/ xylol
Type of clearing agent that is not carcinogenic but will emit fumes that are toxic upon prolonged exposure
Toluene
Type of clearing agent that is no longer available commercially and rapid acting
Benzene
It may damage bone marrow resulting to aplastic anemia
Benzene
Type of clearing agent that causes dizziness it is used for tough tissues- decalcified, nervous, lymph nodes
Also used for embryos- minimum shrinkage and hardening
Chloroform
It is toxic for liver, and does not make tissues transparent
Chloroform
Type of clearing agent that is used for microscopy (oil objective) and it is very penetrating
Cedarwood oil
Can be use for CNS, smooth muscle, skin and cytology, may also be used for paraffin and celloidin sections
Cedarwood oil
Type of clearing agent that is use for clearing embryos, insects and delicate specimens
Aniline oil
Type of clearing agent that causes minimum shrinkage of tissues, wax impregnation- slow to remove
Clove oil
Type of clearing agent that is hepatotoxic which causes liver damage
Carbon tetrachloride
Properties and disadvantages are like chloroform
Carbon tetrachloride
Type of clearing agent that is slow acting and use for double embedding
Methyl benzoate/ salicylate
Type of clearing agent that is both dehydrating and clearing agent, non toxic but with offensive odor
Tetrahydrofuran
Agents that needs a special permission from PDEA
Xylene
Toluene
Benzene
Chloroform