IMPREGNATION

Question 1

Removal of clearing agent from tissue and replacement
of medium that will completely fill all tissue cavities and
give a firm consistency

Answer 1

IMPREGNATION

Question 2

Purposes of Impregnation

Answer 2

Purposes:
- Gives firmer consistency to tissue
- Easier handling and cutting of tissue
- Suitable for thin sections without damage to tissue
and cellular components

Question 3

impregnation a.k.a

Answer 3

infiltration

Question 4

embedding a.k.a

Answer 4

blocking/casting

Question 5

Process by which the impregnated tissue is precisely
positioned and arranged in a mold containing a medium
which is then allowed to solidify.

Answer 5

embedding

Question 6

state the process of embedding

Answer 6

0

Question 7

give atleast 5 characteristics of Impregnation and embedding

Answer 7

• Soluble in processing fluid
• Suitable for sectioning & ribboning
• Molten (30-60°C)
• Translucent, transparent, and colorless
• Stable
• Homogenous
• Capable of flattening after ribboning
• Odorless (Non-toxic)
• Easy to handle
• Inexpensive

Question 8

manual processing

Answer 8

At least four changes of wax are required at 15-
minute intervals

Question 9

Embedding media

Answer 9

Paraffin Wax
Plastic
Gelatin
Celloidin (Collodion)

Question 10

temperature of pw
solid:
molten:

Answer 10

Temperature:
- 21-25°C: solid
- 65-70°C: molten

Question 11

THREE WAYS OF PARAFFIN WAX IMPREGNATION

Answer 11

• Manual
• Automatic
• Vacuum

Question 13

Adv of pw

Answer 13

Rapid processing 24h
Indefinite period of storage of formalin-fixed tissues room temp (n.a decades recovery)
Thin individual sections

Question 14

disadv of pw

Answer 14

Overheated paraffin: brittle specimen
• Prolonged impregnation: tissue shrinkage and
hardening
• Inadequate impregnation: retention of clearing agent
— soft & shrunken tissue -> tissue blocks crumble
when sectioned and breaks when floated out in
water bath.
• Not recommended for fatty tissues

Question 15

histological temp of pw

Answer 15

56-58°C

Question 16

pw temp for decreasing viscosity

Answer 16

above 60 or 65°C

Question 17

traditional advice with paraffin wax is to use
this at about______ its melting point.

Answer 17

2°C above

Question 18

affecting tissue-wax adhesion

Answer 18

crystal morphology
small uniform sized crystals for physical support of specimen

Question 19

how many changes of wax in automatic processing

Answer 19

2-3 changes of wax

Question 20

examples of automatic processors

Answer 20

Leica TP 1020 Tissue Processor
Autotechnicon
Elliot Bench-Type Processor

Question 21

component of vacuum

Answer 21

wax bath, fluid trap, vacuum gauge (760mmHg)

Question 22

Vacuum Embedding

Answer 22

Negative atm pressure within embedding oven or vacuum infiltrator

Question 24

Vacuum source

Answer 24

water or mechanical pressure

Question 25

With vacuum embedding, the time required for complete impregnation is reduced by

Answer 25

25% -75%

Question 26

SUBSTITUES FOR PARAFFIN WAX

Answer 26

PWEDE PARAPLAST WATER SOLUBLE WAX (CARBOWAX) EMBEDDOL DIMETHYL SULPHOXIDE (DMSO) ETHER WAX

Question 27

component of paraplast

Answer 27

higly purified paraffin + synthetic plastic polymer

Question 28

mp of paraplast

Answer 28

56-57°C 54-56°C (winter)

Question 29

adv of paraplast

Answer 29

EDUCCS —ELASTIC & resilient —no residual DEPOSITS on slides —UNIFORM blocks: better ribboning —no prior COOLING req: prev formation of ice crystals —sol w CLEARING agents —no SPECIAL processing schedule

Question 30

good for large dense blocks of brain and bones

Answer 30

PARAPLAST

Question 31

temp increase for automatic

Answer 31

3°C

Question 33

temp inc for vacuum

Answer 33

2-4°C

Question 34

embeddol mp

Answer 34

56-58°C

Question 35

what is embeddol made of

Answer 35

synthetic wax

Question 36

adv of embeddol

Answer 36

BC less brittle and compressible than paraplast

Question 37

paraffin with rubber

Answer 37

tissue mat

Question 38

Semi-synthetic recommended for embedding eyes

Answer 38

Bio/aid

Question 39

component/purposes of bio/aid

Answer 39

semi synthetic eyes

Question 40

component of tissue mat

Answer 40

paraffin + rubber

Question 41

ester wax mp

Answer 41

46-48°C

Question 42

wax that doesnt req clearing

Answer 42

ester wax

Question 43

why does ester wax doesn't req clearing

Answer 43

it is soluble in 95% ethyl alcohol and clearing agents

Question 44

not sol with water

Answer 44

ester wax

Question 45

clearing agents used for ester wax

Answer 45

cellosolve (ethylene glycol monoethky ether) or xylene

Question 46

duration of removal of clearing agent by ester was prior to 3-4 changes of ____

Answer 46

gradual, 3-6hrs pure wax

Question 47

adv of ester wax

Answer 47

HS Harder than paraffin Sol in 95% ethanol not req clearing

Question 48

what type of microtome is utilized when ester wax is used why does it uses this type of microtome

Answer 48

heavy duty microtome (sliding or sledge-type microtome) due to its hardening capacity

Question 49

added to proprietary blends of plastic polymer paraffin waxes reduces infiltration times and facilitates thin sectioning.

Answer 49

Dimethyl sulphoxide (DMSO)

Question 50

component of dmso

Answer 50

proprietary blends of plastic polymer paraffin waxes

Question 51

scavenges residual transition solvent and probably alters tissue permeability by substituting for or removing bound water thus improving infiltration.

Answer 51

Dimethyl sulphoxide (DMSO)

Question 52

how does dmso reduces infiltration time

Answer 52

SA scavanges residual transition solvents alters tissue permeability by substituting for or removing bound water

Question 53

has an unpleasant and annoying oyster or garlic taste

Answer 53

DMSO-paraffin wax

Question 54

plastic polymers, mostly polyethylene glycols

Answer 54

Water Soluble Waxes

Question 55

Water Soluble Waxes mp

Answer 55

38-42°C or 45-56°C

Question 56

incorporated in the majority of proprietary histological paraffin wax blends presently available to improve adhesion, hardness and plasticity.

Answer 56

Polymer waxes

Question 57

what does polymer waxes improve

Answer 57

PAH adhesion, hardness and plasticity.

Question 58

most commonly used polymer wax

Answer 58

Carbowax

Question 59

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

Answer 59

Carbowax

Question 60

how many carbon atoms in carbowax

Answer 60

18

Question 61

is soluble in and miscible with water; hence does not require dehydration and clearing of the tissue

Answer 61

carbowax

Question 62

how does carbowax bypass dehydration and clearing

Answer 62

The tissues are fixed, washed out and transferred directly into the melted Carbowax

Question 63

wax used for demonstration of neutral fats and lipids

Answer 63

carbowax

Question 64

Tissues are not exposed to too much heat so that excessive hardening, shrinkage and brittleness of tissue is avoided; hence, making _____ suitable for many enzyme histochemical studies

Answer 64

Carbowax

Question 65

suitable for many enzyme histochemical studies

Answer 65

carbowax

Question 66

Cytologic details are excellently preserved

Answer 66

carbowax

Question 67

routine processing number of changes of Carbowax

Answer 67

4 changes

Question 68

concentration changes of carbowax

Answer 68

70% 90% 100% 100%

Question 69

temp and time for carbowax

Answer 69

temperature of 56°C are used, at 30 minutes, 45 minutes and 1 hour (with agitation), respectively

Question 70

embedding medium for carbowax impregnation

Answer 70

embedded in fresh Carbowax at 50°C and rapidly cooled in a refrigerator

Question 71

nature of carbowax

Answer 71

hygroscopic nature, Carbowax is very easily dissolved in water

Question 72

very difficult to float out and mount

Answer 72

carbowax

Question 73

remedy for difficulty in floating and mounting for carbowax

Answer 73

Adding soap to water or using 10% Polyethylene Glycol 900 in water will reduce tissue distortion and promote flattening and "floating out" of sections