Infiltration/Impregnation Flashcards
(30 cards)
Infiltration is carried out for what two reasons
- Remove clearing agents from tissue
- Fill up cavities and tissue spaces
- Infiltration method recommended for specimens with large and hollow cavities that tends to collapse
- Disadvantage: Process is slow
Celloidin Infiltration method
Thin celloidin
2-4% ; place the specimen for 5-7 days
Medium celloidin
4-6% ; 5-7 days
Thick celloidin
8-12% ; 3-5 days
- Most common method of infiltration and makes the process rapid because it uses heat
- Not suited for fatty tissues
Paraffin Wax method
Not usually carried out in the lab; recommended only if dehydration must be avoided
Infiltration method for enzyme ad histochemical studies
Gelatin Infiltration Method
Gelatin method will require tissue to be more than
2-3 mm thick
The use of __ in gelatin filtration will prevent mold
Phenol
- Celloidin infiltration method recommended for whole eye specimen.
- Will require use of Gilson’s mixture to store blocks
Dry Celloidin method
- Recommended for bones, teeth, large brain sections and whole organs
- Celloidin infiltration method for bones, brain and teeth specimens
- Will require 70-80% alcohol to store blocks
Wet celloidin metho
Another form of celloidin that is soluble in ether and alcohol
(Low Viscosity Nitrocellulose) or LVN
- Has lower viscosity therefore it can be used in high concentration and can penetrate tissue rapid
- Much preferred than the ordinary celloidin for both impregnation and embedding
Nitrocellulose Method
Produces harder tissue block and allows cutting of thinner sections
Nitrocellulose Method
Disadvantage of LVN
they have the tendency to crack
Remedy for cracks made by LVN
add pasticizers (Oleum ricini or castor oil)
Most common infiltrating agent
Paraffin Wax
Melting point of Paraffin wax
56degC
Paraffin infiltration that uses heat so we need to utilize an oven
Manual Method
temperature range of paraffin oven when in used
55-60degC or approx. 2-5degC higher than the wax melting ping
How many changes of wax is required in manual method?
4 changes
uses autotechnicon that requires 2-3 changes of wax
Automatic Method
Infiltration under negative atmospheric pressure inside the oven
Vacuum method
T/F: In vacuum method, tissue processing time is reduced because tissues are subjected to very high temperature
TRUE
