DEALCOHOLOZATION / CLEARING
▪ Reagents makes tissue TRANSPARENT, hence the name CLEARING, however, not all reagents can make
tissue transparent.
▪ Reagents will also improve the tissue’s REFRACTIVE INDEX
▪ Incomplete clearing = incomplete H and E staining and poor nuclear chromatin patterns
▪ Prolong clearing time = causes tissue to become brittle
▪ Removal of dehydrating agent from tissues to replaced it with a medium that will dissolve the wax with
which the tissues is to be impregnated.
CLEARING AGENTS
1. XYLENE
▪ ROUTINE CLEARING AGENT because it is fast-acting (often used)
▪ With rapid clearing time 30 mins – hours
▪ NOT suited for nervous tissues & lymph nodes
▪ It becomes milky when an incompletely dehydrated tissue is immersed in it
2. BENZENE
▪ Also, fast-acting that’s why it is suited for urgent biopsies
▪ Highly flammable and carcinogenic
▪ Prolong exposure can damage the bone marrow leading to aplastic anemia
3. TOLUENE
▪ Substitute for Xylene and Benzene but not as fast as those 1-2 hours
▪ Disadvantage: Acidifies in a partially filled vessel (nababago yung pH nito if the container is not
fully filled)
4. CHLOROFORM: Used for dense tissues like the uterus
▪ NOT A ROUTINE CLEARING AGENT but it is recommended for clearing tough tissues (skin, fibroid
and decalcified tissues) and can also be used for nervous tissues, lymph nodes and embryos
▪ Tissues tend to float, remedy Wrap tissue in a gauze to keep it at the bottom
▪ Toxic to LIVER
▪ Does not make tissue transparent; Tissues placed on this do not become translucent
▪ Can lead to wax deterioration
5. CEDARWOOD OIL: Also used for dense tissues like the uterus
▪ Clearing time: 2-3 days
▪ Extremely slow clearing agent
▪ Recommended for cytological studies like smooth muscles of skin and CNS tissues
6. ANILINE OIL
▪ Recommended for clearing embryos, insects, and other very delicate spx
▪ Reagents makes tissue TRANSPARENT, hence the name CLEARING, however, not all reagents can make
tissue transparent.
▪ Reagents will also improve the tissue’s REFRACTIVE INDEX
▪ Incomplete clearing = incomplete H and E staining and poor nuclear chromatin patterns
▪ Prolong clearing time = causes tissue to become brittle
▪ Removal of dehydrating agent from tissues to replaced it with a medium that will dissolve the wax with
which the tissues is to be impregnated.
CLEARING AGENTS
1. XYLENE
▪ ROUTINE CLEARING AGENT because it is fast-acting (often used)
▪ With rapid clearing time 30 mins – hours
▪ NOT suited for nervous tissues & lymph nodes
▪ It becomes milky when an incompletely dehydrated tissue is immersed in it
2. BENZENE
▪ Also, fast-acting that’s why it is suited for urgent biopsies
▪ Highly flammable and carcinogenic
▪ Prolong exposure can damage the bone marrow leading to aplastic anemia
3. TOLUENE
▪ Substitute for Xylene and Benzene but not as fast as those 1-2 hours
▪ Disadvantage: Acidifies in a partially filled vessel (nababago yung pH nito if the container is not
fully filled)
4. CHLOROFORM: Used for dense tissues like the uterus
▪ NOT A ROUTINE CLEARING AGENT but it is recommended for clearing tough tissues (skin, fibroid
and decalcified tissues) and can also be used for nervous tissues, lymph nodes and embryos
▪ Tissues tend to float, remedy Wrap tissue in a gauze to keep it at the bottom
▪ Toxic to LIVER
▪ Does not make tissue transparent; Tissues placed on this do not become translucent
▪ Can lead to wax deterioration
5. CEDARWOOD OIL: Also used for dense tissues like the uterus
▪ Clearing time: 2-3 days
▪ Extremely slow clearing agent
▪ Recommended for cytological studies like smooth muscles of skin and CNS tissues
6. ANILINE OIL
▪ Recommended for clearing embryos, insects, and other very delicate spx
