Clearing, Infiltration, Embedding Flashcards
(78 cards)
What is rapid pathologic diagnosis during surgery used for?
If free from cancer
It allows for immediate feedback during surgical procedures.
What is the purpose of enzyme histochemistry?
Diagnostic and research applications
It helps in identifying specific enzymes in tissues.
What substances can be demonstrated through enzyme histochemistry?
Lipids and carbohydrates
These are soluble substances that can be visualized using specific techniques.
What techniques are used for immunofluorescent staining?
Immunofluorescent and immunohistochemical staining
These techniques are used to visualize specific antigens in tissues.
What are specialized silver stains particularly used for?
Neuropathology
They help in visualizing nerve tissues.
What is a cryostat used for?
It allows for frozen section applications
A cryostat is essential in preparing tissue samples for histological analysis.
What are high refractive tissue elements primarily composed of?
Proteins
Lipids are also present in tissue, contributing to the refractive index.
What is the function of clearing agents?
They match the refractive index of proteins and lipids
This minimizes the difference in refractive index, making tissue appear transparent.
Fill in the blank: When two substances have the same refractive index, _______.
light can pass uniformly in the tissue
This reduces scattering and enhances clarity.
True or False: All dealcoholization agents can act as clearing agents.
False
Not all agents serve both purposes.
What is the volume requirement for clearing agents?
Not less than 10x of the tissue
This ensures adequate penetration and effectiveness.
What is a common clearing agent that is highly volatile and toxic?
Xylene
It is widely used in histology for its effective clearing properties.
What is the role of paraffin in tissue processing?
To replace xylene during embedding
Paraffin allows for proper infiltration and preservation of tissue structure.
What characteristics make a good clearing agent?
Rapid penetration, minimal tissue damage, low flammability, and low toxicity
These factors ensure effective and safe tissue processing.
What is the best candidate for a clearing agent?
Xylene
It is known for its rapid and effective clearing properties.
What is impregnation (infiltration) in histology?
Replacing the clearant with a medium to fill natural cavities
This process ensures firm consistency for cutting thin sections.
What are some examples of impregnation agents?
- Paraffin
- Paraplast
- Ester wax
- Bioloid
- Water-soluble waxes
Each agent has specific applications based on tissue type.
What is the purpose of embedding (blocking/casting)?
To place impregnated tissue into a mold for solidification
This step is crucial for preparing tissue for sectioning.
What factors affect the duration of impregnation?
- Size and type of tissues
- Use of vacuum embeddings
- Clearing agent employed
These factors influence how quickly the infiltrating agent penetrates the tissue.
What is the melting point range for paraffin during embedding?
55-60°C
Maintaining the correct temperature is essential for effective embedding.
What is the significance of orientation during embedding?
To arrange tissue in a precise position in the mold
Proper orientation ensures uniform and accurate sectioning.
What is the role of vacuum in embedding?
To reduce the time required for complete impregnation
Negative pressure assists in the penetration of the infiltrating agent.
What is the purpose of disposable embedding molds?
To facilitate easy and accurate identification of specimens
They help avoid confusion during processing.
What is gross examination in pathology?
Macroscopic inspection of pathology specimens
This step is crucial for selecting relevant tissue sections for microscopic diagnosis.
