STEP 2: DEHYDRATION Flashcards
process of removing intercellular and extracellular water from the tissues
dehydration
dehydration involves ________ concentration of alcohol
increasing
starts by 70% ethyl alcohol in water to 95% ethyl alcohol to 100% ethyl alcohol
volume of dehydrating fluid
must not be less than 10 time the volume of the tissue
at 37C will hasten dehydration time for tissue sections that require urgent examination
alcohol
ensures complete dehydration
anhydrous copper sulfate
results that indicate full saturation of dehydrating fluid with water
blue discoloration of copper sulfate crystals
recommended for routine dehydration of tissues
ethyl alcohol
best dehydrating agent
ethyl alcohol
toxic dehydrating agent
methyl alcohol
cellusolve (toxic by inhalation, skin contact and ingestion)
tetrahydrofuran (toxic if ingested or inhaled)
dehydrating agent used for blood and tissue films, and smear preparations
methyl alcohol
dehydrating agent used in plant and animal micro-techniques
butyl alcohol
slow dehydrating agent; for tissues which do not require rapid processing
butyl alcohol
produce less shrinkage and hardening than ethanol
butyl alcohol
rapid acting dehydrating agents
acetone
for most urgent biopsies
acetone
dehydrating agent used for most urgent biopsies
acetone
dehydrating agent the removes most lipids from tissues
acetone
dehydrating agent limited only to small pieces of tissues; not recommended for routine dehydration
acetone
excellent dehydrating and clearing agent
dioxane
tissues can be left in this dehydrating agent for long periods of time without affecting the consistency or staining properties but dehydrated sections tend to ribbon poorly
dioxane
what is Weiseberger’s method?
a dehydration technique where the tissue is wrapped in a gauze bag and suspended in a bottle containing dioxane and a little anhydrous calcium oxide (or quicklime)
the tissue may be transferred from water or normal saline directly to this dehydrating agent and stored in it for months without producing hardening or distortion
cellosolve
disadvantage: combustible at 110-120F, toxic by inhalation, skin contact and ingestion
cellosolve
alternative for cellosolve
Propylene-based glycol ethers
other name for cellosolve
ethylene glycol monoethyl ether
other name for dioxane
diethylene dioxide
used to dehydrate sections and smears following certain stains. it is soluble in alcohol, water, ether, benzene, chloroform, acetone, xylene
triethyl phosphate
may be used for demixing, clearing and dehydrating paraffin sections before and after staining
tetrahydrofuran (THF)
dehydrating agent that does not dissolve out aniline dyes
tetrahydrofuran (THF)
dehydration additive used as a tissue softener for hard tissues such as tendon, nail, or dense fibrous tissue
4% phenol
additives for dehydration
4% phenol
glycerol/alcohol mixture
molliflex
