Dehydration Flashcards
Removal of intracellular and extracellular water from the fixed tissue in preparation for impregnation procedure
Dehydration
Widely used dehydrating agent in the lab
Alcohol
Recommended ration of dehydrating agent to tissue
10:1
Done after fixation and prior to wax impregnation
Dehydration
Characteristics of an ideal dehydrating ageng
- Dehydrate fast
- NOT Evaporate fast
- Evaporate fatty tissues
- NOT harden the tissue excessively
- NOT remove stains
- NOT toxic to the body
- NOT a fire hazard
Use for routine dehydration
Ethyl alcohol (ethanol)
Clear, colorless and flammable
Ethyl alcohol (ethanol)
Best dehydrating agent
Ethyl alcohol (ethanol)
Ethanol is fast acting because is mixes with water and many organic solvent and penetrates the tissue easily (true or false)
True
Not poisonous and not very expensive
Ethyl alcohol (ethanol)
Substitute for ethanol
Isopropyl alcohol
Dehydrating agent for blood and tissue films
Methyl alcohol
Methyl alcohol is a toxic dehydrating agent (true or false)
True
Fixative for smear preparations (bone marrow)
Methyl alcohol
Utilize in plants and animal micro-techniques
Butyl alcohol
A slow dehydrating agent and is recommended for non-urgent works and it also produces less shrinkage and hardening
Butyl alcohol
The strength of the initial alcohol required will depend upon the size, nature of the tissue and the fixative used. (True or false)
True
Recommended starting concentration of alcohol in delicate tissues
30%
Optimum temperature for storing tissue samples
70-80%
Clear, colorless fluid that mixes with water, ethanol, and most organic solvents
Acetone
More miscible with epoxy resins than alcohol
Acetone
Cheap and rapid-acting but has poor penetration
Acetone
Used for urgent biopsies and could remove lipids from the tissue
Acetone
Dehydrating time of acetone
30mins to 2hrs
Dioxane is also known as?
Diethylene dioxide
Readily miscible with water, melted paraffin, alcohol and xylol
Dioxane
Tissues can be left for long periods of time and tends to ribbon poorly
Dioxane
Expensive and extremely dangerous
Dioxane
Dioxane should be used readily and the room should be not properly ventilated because it produces vapors
False (not be used readily and the room should be properly ventilated)
Cellosolve is also known as?
Ethylene glycol monoethyl ether
Tissue samples with cellosolve can be stored for months without producing hardening/distortion unlike alcohol (true or false)
True
Cellosolve is combustible at how many degree Farenheit
110-120degree F (43.3-48.8degree C)
Toxic by inhalation, skin contact, and targets reproductive, fetal, urinary and blood systems
Cellosolve
This can be used in cellosolve instead of Ethylene glycol monoethyl ether to avoid side effects
Propylene-based glycol ether
Removes water very readily
Triethyl phosphate
Produces very little distortion and hardening
Triethyl phosphate
The amount of dehydrating agent should not be less than 10 times the volume of the tissue (true or false)
True
Soluble in alcohol, water, ether, benzene, chloroform, acetone and xylene
Triethyl phosphate
Both dehydrating and alcohol agent like dioxane
Tetrahydrofuran
Could dissolve fat and may be used for refixing, clearing, and dehydrating paraffin section before and after staining
Tetrahydrofuran
Miscible with lower alcohols, ether, chloroform, acetone, benzene, and xylene
Tetrahydrofuran
It will not dissolve aniline dyes and is toxic when ingested or inhaled
Tetahydrofuran
An eye and skin irritant
Tetrahydrofuran
Prolonged exposure of THD up to 6months may cause conjunctival irritation (true or false)
True
Act as a tissue softener for hard tissue
4% phenol
Added to each of the 95% ethanol baths
4% phenol
