CLEARING Flashcards
aka dealcoholization
CLEARING
Clearing agents are fully miscible to
ethanol and paraffin wax, and mounting media
Remove a substantial amount of fat from the tissue which otherwise presents a barrier to wax infiltration
CLEARING
done after dehydration or before infiltration; after staining or before mounting
CLEARING
Removal of dehydrant
CLEARING
gives structure back to the tissue
paraffin
how many changes of xylene in clearing
2 changes of xylene
- xylene (1st: 25mins), xylene (2nd: 45mins)
most important and critical part of tissue
processing because as much as possible it should preserve the tissue
in the living state.
Fixation
unique aliphatic substitute for xylene
Pro-par clearant
acts as an intermediate solvent/middle man so
paraffin could fully infiltrate the tissue
Clearing agent
specimen thickness in clearing
4mm
cause brittleness and more difficult to cut
Prolonged clearing:
fully miscible with both ethanol
and paraffin wax
Intermediate solvent
a good cleaning and clearing agent
xylene
specimen vol in clearing
20x the tissue volume/size
how many changes for Pro-par clearant
3 changes (45mins, 45mins, 45mins
Factors affecting Clearing
boiling point, viscosity and refractive index
It evaporates quickly in paraffin oven and can,
therefore, be readily replaced by wax during
impregnation and embedding
. XYLENE/XYLOL
Suitable for urgent biopsies which it clears within 15-30 minutes.
. XYLENE/XYLOL
It is the most rapid and common clearing agent
. XYLENE/XYLOL
substitute for xylene or benzene
TOLUENE
Toxic: CNS, Resp, Integumentary, Liver dse,
nephrotoxicity, conjunctivitis, teratogenic and fetotoxic
. XYLENE/XYLOL
better at preserving tissue structure
TOLUENE
Routine clearing agent
. XYLENE/XYLOL
Highly concentrated solutions will emit fumes that are toxic upon prolonged exposure
TOLUENE
Slower than xylene and benzene
TOLUENE
It volatilizes rapidly in paraffin oven and is therefore easily eliminated from the tissue
BENZENE
It volatilizes rapidly in paraffin oven and is therefore easily eliminated from the tissue
BENZENE
It is rapid acting, hence is recommended for urgent biopsies (15-60mins)
BENZENE
it is recommended for tough/dense tissues leg skin, uterus, muscle, fibroid and decalcified tissues for nervous tissues, lymph nodes
CHLOROFORM
Extremely carcinogenic to man causing APLASTIC ANEMIA
BENZENE
It is suitable for large tissue specimen
CHLOROFORM
Miscible with absolute alcohol
CHLOROFORM
Tissues tend to float
CHLOROFORM
Cause less brittleness than xylene
CHLOROFORM
Toxic to the liver, should be used in well-ventilated room
CHLOROFORM
clearing agent For delicate specimens
ANILINE OIL
Its vapor may attack the rubber seal used in vacuum
impregnating bath
CHLOROFORM
Embryos (bouin’s), insects,
ANILINE OIL
it has a dangerous toxic gas
CHLOROFORM
For central nervous system tissues and cytological studies, particularly of smooth muscles and skin
CEDARWOOD OIL
clearing agent that has offensive odor
TETRAHYDROFURAN
Extremely slow clearing agent (plus days)
CEDARWOOD OIL
2-3 days (paraffin)
5-6days (celloidin)
clearing agent that Makes tissue brittle
CLOVE OIL
clearing agent from plant extracts
TERPENES
Similar to chloroform but cheaper
CARBON TETRACHLORIDE (CCl4) OIL
using graupner’s , how many hours/ minutes using paraffin
3x in 90min
clear both paraffin and celloidin section
CEDARWOOD OIL
clearing agent that is non toxic
TETRAHYDROFURAN
clearing agent where Celloidin is dissolved
CLOVE OIL
Superior to dehydrating and clearing agents
TETRAHYDROFURAN
clearing agent where aniline dyes are removed
CLOVE OIL
using graupner’s , how many hours/ minutes using dioxane
3x in 4hrs
Prevent hepatotoxin
CARBON TETRACHLORIDE (CCl4) OIL
clearing agent for Double embedding
METHYL BENZOATE/SALICYLATE
Also called as Esters
METHYL BENZOATE/SALICYLATE
clearing agent that is Good for manual processing
METHYL BENZOATE/SALICYLATE
clearing agent for Papanicolaou smears
CARBO-XYLENE
Temp. of paraffin: in clearing
50-85C
clearing agent for Thick mucinous
. CARBO-XYLENE
