Infiltration (MTAP 2)

Prolonged impregnation

It will cause excessive tissue shrinkage and hardening, making the cutting of sections difficult

Overheated paraffin

It makes the specimen brittle

Retention of the clearing agent

Inadequate impregnation will promote:

• Bones

• Teeth

• Brains

• Eyes

Which tissue(s) is/are difficult to infiltrate and needs longer immersion for proper support?

Fatty tissues

Paraffin processing is not recommended for:

Autotechnicon

This method of infiltration requires only 2-3 changes to remove the clearing agent and properly impregnate the specimen

Tissue Transfer Type (3T)

What is the most common type of Autotechnicon?

Fluid Tissue Type (FTT)

Type of Autotechnicon that is enclosed; tissue stays within the chamber, where the reagent process is pumping in and out

Vacuum

• Method of infiltration that undergoes wax impregnation under negative atmospheric pressure inside an embedding oven

• Recommended for urgent biopsies, for delicate tissues

2-4°C above the melting point of the wax

Vacuum embedding is maintained at a temperature of:

Stopcock

It is provided to prevent water from being sucked back into the trap bottle and vacuum chamber when the water or suction pump is closed

TRUE

TRUE OR FALSE

Benzene and Xylene are easily removed from tissues

TRUE

TRUE OR FALSE

Chloroform and Cedarwood oil are more difficult to remove from tissues and require more frequent wax changes

56-57°C

It is the melting point of Paraplast

Paraplast

• Substitute for paraffin wax; mixture of highly purified paraffin and synthetic plastic polymers

• Recommended for bones and brain specimens

Embeddol

• Similar to Paraplast but with a higher melting point

• Less brittle and less compressible than Paraplast.

56-58°C

It is the melting point of Embeddol

Bioloid (Bioaid)

Semi-synthetic wax recommended for embedding eyes

Tissue Mat

Product of paraffin, containing rubber, with the same property as Paraplast.

Ester wax

Has a lower melting point but is harder than paraffin

46-48°C

It is the melting point of Ester wax

Cellosolve

It is also known as Ethylene glycol monoethyl ether

Carbowax

A polyethylene glycol containing 18 or more carbon atoms, which appears solid at room temperature.

Carbowax

GUESS THE WAX:

Advantages:

• Eliminates dehydration and clearing process

• Cytological details are well-preserved

Disadvantages:

• Difficult to float out when cut

• Does not remove neutral fats and lipids

Dimethyl sulfoxide (DMSO)

Has unpleasant and annoying oyster or garlic taste

Celloidin (Collodion)

• It is a purified form of nitrocellulose soluble

• For specimens with large hollow cavities which tend to collapse

Celloidin

• Permits cutting of tissue sections which are thicker than in paraffin wax

• Recommended for processing of neurological tissues

Celloidin

It does not require heat during processing

Wet Celloidin

• Recommended for bones, teeth, large brain sections and whole organs

• The tissue block is then stored in 70–80% alcohol until ready for cutting.

Dry Celloidin

Preferred for processing of whole eye sections.

Uses Gilson’s mixture for storage.

Gilson’s mixture

It is made up of equal parts of chloroform and cedarwood oil.

Low Viscosity Nitrocellulose (LVN)

A form of celloidin which has lower viscosity and is highly explosive

Oleum ricini and Castor oil

Which remedy is used for LVN if tissues tend to crack?

Gelatin infiltration

• Recommended for delicate specimens and frozen tissue sections

• It prevents fragmentation of tough and friable tissues when frozen sections are cut.

1% phenol

It serves to prevent the growth of molds

5-10 degC lower than the wax melting point

Water bath temperature should be:

Poly-L-Lysine

This adhesive must be used within a few days after they are prepared, since its effectiveness as an adhesive slowly decreases in time

APES

Very useful in cytology, particularly for cytospin preparations of proteinaceous or bloody material