Impregnation and Embedding Flashcards
(73 cards)
[3] Types of tissue impregnating medium
[PCG]
- Paraffin wax
- Celloidin (collodion)
- Gelatin and plastic
Simplest, most common and best embedding medium.
Paraffin wax impregnation
Very rapid.
Paraffin wax impregnation
Melting point of paraffin wax impregnation.
56°C
Thin sections maybe cut without undue distortion.
[dis/advantages]
Advantages
Rapid, and can be prepared within 24 hrs.
[dis/advantages]
Advantages
Tissue blocks may be stored in paraffin for an indefinite period of time after impregnation.
[dis/advantages]
Advantages
Permits staining.
[dis/advantages]
Advantages
Overheated paraffin can make the specimen brittle.
[dis/advantages]
Disadvantages
Prolonged impregnation will cause excessive shrinkage and hardening.
[dis/advantages]
Disadvantages
Inadequate impregnation will cause retention of the clearing agent.
Disadvantages
Paraffin processing is not recommended for fatty tissues.
Disadvantages
[3] Ways which praffin wax may be performed.
[MAV]
- Manual processing
- Automatic processing
- Vacuum processing
With melting point = 56 C is normally used for routine work.
[ways of pw may be performed]
Manual processing
If the lab temperature = 20-24 C
- paraffin wax MP to use:
(54-58 C)
If the lab temp. = 15-18 C
paraffin wax MP to use:
50-54 C
Usually only 2-3 changes of wax are required to remove the clearing agent.
[ways of pw may be performed]
Automatic processing
Parts: 12 individual processing steps
[ways of pw may be performed]
Automatic processing
Transfer arm
[ways of pw may be performed]
Automatic processing
Electrical clock
[ways of pw may be performed]
Transfer arm
Its embedding involves the wax impregnation under negative atmospheric pressure inside an embedding oven.
[ways of pw may be performed]
Vacuum embedding
Provides more rapid wax penetration of tissue.
[ways of pw may be performed]
Vacuum embedding
The time required for complete impregnation is reduced from 25-75% of the normal time required for tissue processing.
[ways of pw may be performed]
Vacuum embedding
[6] Paraffin was substitues
[PEB, TEC]
- Paraplast
- Embeddol
- Bioloid
- Tissue mat
- Ester wax
- Carbowax