02 Embedding and Impregnation

Question 1

___C temperature prevents cracking of the tissue block

Answer 1

10C

Question 1

a process of saturating the tissue with a medium, usually liquid paraffin, to permeate or fill up the natural cavities, spaces, and interstices of the tissue

Answer 1

impregnation

Question 2

in embedding, the paraffin should appear ___ and ___ and no layering should be formed

Answer 2

clear
homogenous

Question 3

paraffin rapidly converts from solid to liquid at ___C

Answer 3

56-58C

Question 4

type of paraffin wax:

amorphous, slightly yellowish substance

Answer 4

celloidin

Question 5

the less purified form of celloidin

Answer 5

collodion or nitro-cellulose

Question 6

T/F: celloidin does not require heat

Answer 6

T

Question 7

describe the consistency of celloidin

Answer 7

rubbery

Question 8

substitute for paraffin wax:

mixture of highly purified paraffin and synthetic plastic polymers

Answer 8

paraplast

Question 9

substitute for paraffin wax:

less brittle and less compressible than paraplast

Answer 9

embeddol

Question 10

substitute for paraffin wax:

a semisynthetic wax recommended for embedding eyes

Answer 10

bioloid

Question 11

substitute for paraffin wax:

has a lower melting point (46-48C), but is harder than paraffin

Answer 11

ester wax

Question 12

substitute for paraffin wax:

not soluble in water, but is soluble in 95% ethyl alcohol and other clearing agents

Answer 12

ester wax

Question 13

melting point of water soluble waxes

Answer 13

38-42C or 45-46C

Question 14

substitute for paraffin wax:

a polyethylene glycol is suitable for many enzyme histochemical studies

Answer 14

carbowax

Question 15

in using dimethyl sulphoxide, histotechnologists may experience an unpleasant and annoying ___ or ___ taste

Answer 15

oyster
garlic

Question 16

T/F: sectioning of paraffin is difficult at low temperatures

Answer 16

F (high)

Question 17

type of paraffin wax:

allows higher concentration to be used; greater speed of impregnation

Answer 17

low viscosity nitrocellulose (LVN)

Question 18

type of paraffin wax:

final block is harder, allowing thinner sections to be cut

Answer 18

low viscosity nitrocellulose (LVN)

Question 19

type of paraffin wax:

have a tendency to crack down during handling and staining; highly explosive

Answer 19

low viscosity nitrocellulose (LVN)

Question 20

in double embedding, the tissue is first impregnated with ___, and subsequently blocked in ___

Answer 20

celloidin
paraffin wax

Question 21

this provides extra degree of resilience when cutting hard tissues

Answer 21

double embedding

Question 22

type of paraffin wax:

main use is in double embedding technique with ester wax or paraffin wax

Answer 22

agar

Question 23

type of paraffin wax:

cohesive agent for multiple fragments or friable tissue

Answer 23

agar

Question 24

type of paraffin wax: has a lower melting point than aga

Answer 24

gelatin

Question 25

type of paraffin wax: main use in the production of whole organ sections

Answer 25

gelatin

Question 26

type of paraffin wax: tissues can be embedded directly from water

Answer 26

water-soluble waxes

Question 27

type of paraffin wax: restricted due to the violent diffusion currents which can lead to the complete fragmentation of the section

Answer 27

water-soluble waxes

Question 28

plastic embedding medium: reduces antigenicity, toxic, and damages tissue

Answer 28

epoxy

Question 29

epoxy: bisphenol A

Answer 29

araldite

Question 30

epoxy: glycerol

Answer 30

epon

Question 31

epoxy: cyclohexene dioxide

Answer 31

spurr

Question 32

plastic embedding medium: not often used

Answer 32

polyester

Question 33

plastic embedding medium: used extensively for light microscopy

Answer 33

acrylic

Question 34

mold for embedding: molds for routine work and are widely used

Answer 34

leuckhart's embedding mold

Question 35

mold for embedding: consists of 2 L-shaped pieces of metal

Answer 35

leuckhart's embedding mold

Question 36

mold for embedding: arranged on a glass metal plate to form a mold of desired size

Answer 36

leuckhart's embedding mold

Question 37

mold for embedding: consist of a series of interlocking plates resting on a flat metal base, forming several compartments

Answer 37

compound embedding unit

Question 38

mold for embedding: has the advantage of embedding more specimens at a time

Answer 38

compound embedding unit

Question 39

mold for embedding: used in positioning histological tissues accurately in base molds

Answer 39

plastic embedding ring and base mold

Question 40

mold for embedding: disposable embedding mold

Answer 40

peel-a-way

Question 41

mold for embedding: can be placed directly in the chuck of the microtome

Answer 41

peel-a-way

Question 42

mold for embedding: made from thick paper or cardboard paper

Answer 42

paper boat

Question 43

mold for embedding: cheap to make and allow blocks to be stored without being removed

Answer 43

paper boat

Question 44

mold for embedding: provide easy and accurate identification of specimens, thereby avoiding confusion and interchange of tissue blocks

Answer 44

paper boat

Question 45

mold for embedding: convenient molds for busy routine laboratory, one block being embedded in each compartment

Answer 45

plastic ice tray

Question 46

in using plastic ice tray, blocks are easily removed by flexing the plastic trays and by smearing the inside of the mold with ___ or ___ ___

Answer 46

glycerin liquid paraffin

Question 47

mold for embedding: ideal for embedding fragmentary biopsies

Answer 47

watch glass

Question 48

T/F: in using watch glass, it is essential to smear with glycerin as the blocks would be hard to remove

Answer 48

F (no need to smear)

Question 49

mold for embedding: used for small fragments which have been processed (bone marrow) which concentrates them without the damage caused by orientation with forceps

Answer 49

test tube

Question 50

mold for embedding: used for embedding tissue intended for EM microscopy

Answer 50

methacrylate plastic resin (EPON resin)