MTAP (Dehydration- Impregnation) Flashcards
Removes fixatives and water from the tissue and replaces them with a dehydrating fluid.
Dehydration
Dehydrating fluids are generally used in?
increasing strengths
List the common alcohol dehydrating agents
- Alcohol
- Ethanol
- Methyl Alcohol
- Butyl Alcohol
- Denatured Alcohol
- Isopropyl Alcohol
Most commnon dehydrating agent
Alcohols
Best dehydrating agent
Ethanol
Dehydrating agent used for blood and tissue films
Methyl Alcohol
Dehydrating agent used in plant and animal microtechniques
Butyl Alcohol
Denatured Alcohol is a product of?
Ethanol + minute amount of methanol
Used as both fixative & dehydrating agent
Acetone
A very expensive dehydrating agent and is monitored by the government
Acetone
Used as both a dehydrating & clearing agent
Dioxane and Tetrahydrofuran (THF)
The process of replacing the dehydrating fluid with a substance miscible with both the dehydrating and impregnating medium.
Dealcoholization
Most Common Clearing Agent
Xylene
Colorless clearing agent. Used as a clearing agent during tissue processing and as a dewaxing agent during staining
Xylene
Clearing time of Xylene
½ to 1 hour
A clearing agent that is better at preserving tissue structure than xylene
Toluene
A clearing agent that is more tolerant of small amounts of water left in tissues
Toluene
A clearing agent that is more expensive and more toxic than xylene
Toluene
A clearing agent that is slower in action than xylene. Causes less brittleness
Chloroform
What are the clearing agents that are used in specialized tissue processing
Methyl Benzoate & Methyl Salicylate
A clearing agent that clears both paraffin and celloidin sections during the embedding process
Cedarwood Oil
A clearing agent that penetrates and clears tissues rapidly
Benzene
A clearing agent that causes minimum shrinkage of tissues
Clove Oil
Process of replacing the clearing agent with the infiltrating medium
Impregnation
Process of replacing the dehydrating fluid with miscible with BOTH the dehydrating and impregnating medium
Clearing
A clearing agent that is NOT normally used as a routine clearing agent
Aniline Oil
A clearing agent that is used as natural alternatives in tissue processing
Citrus Fruit Oils
A clearing agent that is recommended for clearing embryos, insects, and delicate specimens and can clear 70% alcohol
Aniline Oil
Simplest, most common, and the BEST infiltrating medium
Paraffin Wax
Also known as Infiltration
Impregnation
Four Types of Tissue Impregnation
- Paraffin Wax
- Gelatin
- Plastics
- Celloidin
Impregnation ratio
25:1
Who introduced Paraffin Wax?
Butschi
A type of tissue impregnation that is a purified form of nitrocellulose and soluble in many solvents
Celloidin
This has better resolution compared to Paraffin wax
Pellet
Temperature of paraffin wax should be around _________ and ________ above the melting point
55-60C; 2-5C above the MP
Plastics is classified based on chemical composition into?
◆ Epoxy
◆ Polyester
◆ Acrylic
NOT recommended for fatty tissue
Paraffin Wax
A type of tissue impregnation that is used in histochemical and enzyme studies
Gelatin
Plastics provide high-resolution light microscopy for thinner tissue sections less than?
less than 4-6 µm
A type of tissue impregnation that prevents fragmentation of tough and friable tissues. Also used for delicate specimens and frozen tissue sections
Gelatin
A type of tissue impregnation that is rarely used except when dehydration is to be avoided
Gelatin
A type of tissue impregnation that is used for undecalcified bone.
Plastics
Celloidin is suitable for?
- Specimens with large hollow cavities (e.g., eyes and brain)
- Mixed-consistency tissues
