dehydration and clearing Flashcards
process of removing intercellular and extracellular water from the tissue following fixation and prior to wax impregnation
dehydration
removal of water by evaporation from solid, semi-solid, or liquid state
drying
10% formalin and Bouin’s
1) 70% - 100& alcohol III = __ - __ hours
2) xylol I = __ - __ hours
3) xylol II = __ hour
1) 3-12 hours
2) 1-2 hours
3) 1 hour
characteristics of an ideal dehydrating agent
- should dehydrate rapidly without shrinkage or distortion of tissue
- should not evaporate very fast
- should be able to dehydrate even fatty tissue
- should not harden tissues excessively
- should not remove stains
- should not be toxic to the body
- should not be a fire hazard
commonly used dehydrating agents
alcohol - most commonly used
acetone
dioxane
cellosolve
triethyl phosphate
tetrahydrofuran
____ ____is the recommended dehydrating agent for routine dehydration. considered to be the best dehydrating agent because it is ___ ___.
ethyl alcohol, fast-acting
___ toxic dehydrating agent, primarily employed for blood and tissue films and for smear preparation
methyl alcohol
___ is a slow dehydrating agent, produce less shrinkage and hardening than ethyl alcohol. recommended for tissues that do not require rapid processing
butyl alcohol
___ is a cheap dehydrating agent utilized for urgent biopsies which dehydrate in 1/2 to 2 hours. It is a clear, colorless fluid that mixes with water, ethanol, and most organic solvents
acetone
___ is a excellent dehydrating and clearing agent that is readily miscible in water, melted paraffin, alcohol, and xylol.it produces less tissue shrinkage than alcohol. however, it is extremely dangerous
dioxane
___ dehydrates rapidly. tissues may be transferred from water or saline directly to cellosolve and stored for months without producing hardening or distortion.
cellosolve
___ removes water readily and produce very little distortion and hardening of tissue
triethyl phosphate
___ reagent that both dehydrates and clears tissue since it is miscible in both water and paraffin.
tetrahydrofuran
two types of clearing agents: ___ and ___
organic solvents and oils
___ clearing of choice
xylol