DEHYDRATION Flashcards
The process of removing intercellular and extracellular water from the tissue following fixation and prior to wax impregnation
DEHYDRATION
Embryonic tissues starts dehydration at what percent
30% ethanol
Alcohol recommended for routine dehydration
Ethyl alcohol
Best dehydrating agent
Fast acting
Ethyl alcohol
Toxic dehydrating agent
Methyl alcohol
Dioxane
Cellosolve
Tetrahydrofuran
For blood and tissue films
Smear preparation
Methyl alcohol
Utilized in plant and animal micro-techniques
Butyl alcohol
Slow dehydrating agent
Butyl alcohol
Formalin fixed tissue must be transferred directly to what alcohol?
Higher grade of alcohol 85-95% alcohol
It tends to harden only the surface of the tissue while deeper parts are not completely penetrated
Concentrated alcohol
95% to absolute
To avoid hardening of the surface only use?
70% gradually increased to 95% is used
It tends to macerate the tissue
Prolonged storage in below 70% alcohol
Temperature that hasten dehydration time
Used for urgent exam
37C
For fragmentary biopsies
Temp 37C
What to do to ensure complete dehydration
This will accelerate dehydration by removing water from the dehydrating fluid
Layer of anhydrous copper
Sulfate 1/4 inch deep covered with filtered paper
It is an indication of full saturation of dehydrating fluid with water
Blue discolorization of copper sulfate crystals
More miscible with epoxy resins than alcohol
Acetone
Highliy flammable
Acetone
Rapid action but penetrates tissue poorly
Acetone
Lipids are remove from the tissue with this dehydrating agent
Acetone
Other term of dioxane
Diethylene dioxide
Dehydrating and clearing agent
Dioxane
Tetrahydrofuran
It tends to ribbon poorly
Dioxane
Method that tissue is wrapped in gauze bag and suspended with dioxane and anhydrous calcium oxide
Weiseberger’s method
Dehydrates rapidly
Cellosolve
Cellosolve
Ethylene glycol monoethyl ether
Ethylene glycol ether is combustible in what temp?
110-120F
Used to dehydrate section and smears
Triethyl phosphate
THF
Tetrahydrofuran
Miscible with Water Melted paraffin Alcohol Xylol
Dioxane
Miscible in water and paraffin Lower alcohols Ether Chloroform Acetone Benzene Xylene
Tetrahydrofuran
May be used for demixing,
Clearing,
Dehydrating paraffin section
THF
Hard tissues can be immersed in
Glycerol
Alcohol mixture or in
MOLLIFLEX
Tissues can be left with this reagent for long period of time without affecting the consistency and staining properties
Dioxane
Two types of dioxane
Graupners
Weiseberger
Only to small pieces
Acetone
Indicator of h2o saturation
Anhydrous copper sulfate
