IMPREGNATION & EMBEDDING Flashcards
This is the process whereby the clearing agent is completely removed from the tissue and replaced by a medium that will completely fill all the tissue cavities and give a firm consistency to the specimen
Impregnation
Impregnation is also called …
Infiltration
It is the process by which the impgregnated tissue is placed into a precisely arranged position in a mold containing a medium which is then allowed to solidify
Embedding
Embedding is also called …
casting/blocking
Embedding and infiltrating mediums should be soluble in processing fluids
true or false
true
embedding and infiltrating mediums must be molten between what temperatures?
30C and 60C
What is the medium used to infiltrate the tissue and is usually the same medium utilized for impregnation
embedding medium
What are the 4 types of impregnation and embedding mediums?
PPCG
- PARAFFIN WAX
- PLASTIC
- CELLOIDIN
- GELATIN
Celloidin is also called …
collodion
This is the simplest, most common, and best embedding medium
paraffin wax
this is used for routine tissue processing
paraffin wax
This is a polycrystalline mixture of solid hydrocarbons produced during refining of coal and mineral oils
Paraffin
Paraffin melts at what temperatures?
65C to 70C
This is solid at room temperature
paraffin
Paraffin wax at 56C to 58c are the most commonly used for what?
histological use
Paraffin, at its melting point, tends to be what?
Slightly viscous
Viscosity decreases as the temperature increases
true or false
true
The traditional advice with paraffin wax is to use this at what temperature?
2C above its melting point
Wax hardness (viscosity) of paraffin depends on what?
- molecular weight of the components
- ambient temperature
To decrease viscosity and improve filtration, what do technologists do?
they increase the temperature
For paraffin, to decrease viscosity and improve infiltration of the tissue, the technologists often increase the temperature to what temperature?
to above 60C ot 65C
High molecular weight mixtures melt at lower temperatures than waxes comprised of lower molecular weight fractions
true or false
false
higher temperatures
High molecular weight mixtures melt at lower temperatures than waxes comprised of lower molecular weight fractions
true or false
false
higher temperatures
Paraffin wax is traditionally marketed by its melting points which range from what?
39C to 68C
Tissu-wax adhesion depnds upon the what?
crystal morphology of the embedding medium
These provides better physical support for specimens through close packing
Small, uniform sized crystals
Small, uniform sized crystals provide better physicaly support for specimens through what?
through close packing
Crystalline morphology of paraffin eax can be altered by incoportating what?
additives
The incoporation of additives result in a less brittle, more heterogeneous wax with good cutting characteristics
true or false
false
less brittle, more homogeneous, with good cutting characteristics
The incoporation of additives result in a less brittle, more heterogeneous wax with good cutting characteristics
true or false
false
less brittle, more homogeneous, with good cutting characteristics
There is consequently more deformation during thin sectioning
true or false
false
less deformation
There is consequently more deformation during thin sectioning
true or false
false
less deformation
This does not appreciably affect crystal size
setting temperature
They are an important source for historical studies in medicine
formalin-fixed, paraffin-embedded tissues
What are the types of Microtomes?
FRRUCS
- Freezing
- rotary
- rocking
- ultrathin
- Cryostat
- Sliding
It is an example of a heavy duty microtome
Sliding
What are the 3 general methods for infiltration?
- Paraffin
- Celloidin
- Gelatin
What are the 3 methods under paraffin?
- Manual
- Automatic
- Vacuum
What are the substitutes for Paraffin wax?
- Paraplast
- Embeddol
- Ester wax
- Bioloid
- Tissue mat
- Carbowax
This is a method used for celloidin impregnation that is recommended for the bones, brain, teeth, and whole organs
Wet celloidin method
This is a method used for celloidin impregnation that is recommended for the eyes
dry celloidin method
How many percent celloidin does the THIN CELLOIDIN contain?
2-4 %
For how many days must the THIN CELLOIDIN be left at?
5-7 days
How many percent celloidin does the MEDIUM CELLOIDIN contain?
4-6% celloidin
For how long must the medium celloidin be immersed in 4-6% celloidin?
5-7 days
What percent of celloidin must THICK CELLOIDIN contain?
8-12% celloidin
For how long must the THICK CELLOIDIN be immersed in 8-12% celloidin?
3-5 days
f the specimen that you are processing have bigger spaces of cavities and the specimen is bigger, IT WILL MAKE THE PROCESS LONGER.
true or false
true
This is an equipment that is used for cutting tissues.
Microtome
This has a melting point of 46-48C
Ester wax
This is recommended for enzyme studies
Carbowax
It is hygroscopic or water-soluble
Carbowax
It is a substitute for paraffin that is recommended for eye specimens
Bioloid
It is a substitute for paraffin that is recommended for bones and brain specimen
Paraplast
What is the melting point of Paraplast?
56-57C
It is a substitute for paraffin wax that has a melting point of 56-58C
Embeddol
This method is under negative atmospheric pressure inside the oven
Vacuum method
This is the routine infiltration method
Paraffin wax infiltration
What are the 2 types of autotechnicon?
- Tissue type transfer
- Fluid transfer type
The fluid transfer type is also called …
Also called as Enclosed Type
The Tissue Transfer Type is also known as the …
Dip and Dunk type
What are the parts of an Autotech?
STEC10
- Spring loaded plunger
- Transfer arm
- Electric clock
- Cover plate
- 10-12 1L capacity beakers
The first 2 beakers of an autotechnicon contain what?
FORMALIN
Beaker’s 3, 4, 5 of an autotechnicon contains what?
ALCOHOL in INCREASING concentration
Beaker’s 6, 7, 8 of an autotechnicon contains what?
XYLENE, 3 changes of xylene
Beaker’s 9 and 10 of an autotechnicon contains what?
contains PARAFFIN WAX
Also called as Timing Disk
Electric clock
It determines the duration of the process
Electric clock
It facilitates automatic transfer of tissue/s from one reagent to another
Transfer arm
Its purpose is to cover all the beakers
Cover plate
The opening and closing function of the cover plate is AUTOMATIC and done by what?
Spring loaded plunger
This facilitates the removal of the cover plate
Spring loaded plunger
This is the type of autotechnicon wherein the tissue/s stays within the chamber where the reagent for each process is pump in and out
Fluid transfer type
What are the 2 advantages of the Fluid Transfer type?
- Drying of tissues is prevented
- Vapors are vented through filters
Paraffin wax is compatible with many stains
true or false
true
What must be the approximate temperature in the manual processing?
2-5℃ higher than the wax melting point
This is the cause of specimen brittleness
Overheated paraffin
This will cause excessive tissue shrinkage and hardening, making the cutting of sections difficult
Prolonged impregnation
This will promote retention of the clearing agen
Inadequate impregnation
What happens to the tissues in cases of inadequate impregnation?
tissues become soft and shrunken
What happens to tissue blocks in cases of inadequate impregnation?
tissue blocks crumble when sectioned and break up when floated out in a water bath
What are examples of tissues that are difficult to infiltrate?
BBET
- Bones
- brain
- Eyes
- teeth
Tissues that are difficult to infiltrate require what?
long immersion for proper support