Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

[2S] HP LAB > clearing > Flashcards

clearing Flashcards

1
Q

process by which alcohol or a dehydrating agent is removed from the tissue and replaced with a substance to dissolve wax or mounting medium

A

Clearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why is alcohol dissolved during the clearing process

A

paraffin (wax used for tissue impregnation) does not mix with alcohol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T/F The first step of clearing involves replacing water in the tissue with alcohol during dehydration

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

most commonly used clearing agent to dissolve alcohol in tissues

A

Xylene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

function of a clearing agent used after alcohol dehydration

A

mixes with alcohol and removes it from the tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens when the clearing agent is used after tissue section staining?

A

makes the tissue preparation transparent for microscopic examination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

when tissue is cleared directly from water, what is the role of the clearing agent?

A

improves the refractive index of the tissue without dealcoholization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Odd One Out: Characteristic of a good clearing agent
A) Miscible with alcohol
B) Dissolves aniline dyes
C) Makes tissues transparent
D) Easily removed by paraffin wax

A

B) Dissolves aniline dyes – a good clearing agent should not dissolve aniline dyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Odd One Out: acceptable property of a clearing agent
A) Causes excessive shrinkage
B) Miscible with alcohol
C) Easily removed by paraffin
D) Makes tissues transparent

A

A) Causes excessive shrinkage – A good clearing agent should not cause excessive shrinkage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: A good clearing agent should evaporate quickly in a water bath.

A

False – should not evaporate quickly in a water bath.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the boiling point of a clearing agent affect the process?

A

Clearing agents with low boiling points are more readily replaced by melted paraffin wax.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T/F Clearing agents with high viscosity can slow the penetration of the clearing agent into the tissue.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

effect of prolonged exposure to a clearing agent on the tissue?

A

cause the tissue to become brittle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Odd One Out: NOT a factor in choosing clearing agent
A) Cost and convenience
B) Processor system used
C) Ability to dissolve paraffin
D) Type of tissue and processing method

A

C) Ability to dissolve paraffin – The clearing agent should not dissolve paraffin, but it should be easily removed by it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

T/F: The ease of removing the clearing agent by molten paraffin wax is a key consideration when selecting a clearing agent.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

commonly used clearing agent in tissue processing

A) Benzene
B) Cedarwood Oil
C) Xylene
D) All of the above

A

D) All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Odd One Out: Which of the following is NOT a commonly used clearing agent?
A) Xylene
B) Carbon tetrachloride
C) Methanol
D) Toluene

A

C) Methanol – Methanol is a dehydrating agent, not a clearing agent.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

most commonly used clearing agent, suitable for tissue blocks less than 5 mm in thickness

A

Xylene (Xylol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

T/F: Xylene is used for both embedding and mounting procedures in routine histologic processing.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

typical clearing time for Xylene?

A

½ to 1 hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Odd One Out: Advantage of Xylene
A) Miscible with alcohol and paraffin
B) Most rapid clearing agent
C) Extracts aniline dyes
D) Evaporates quickly in a paraffin oven

A

C) Extracts aniline dyes – Xylene does not extract aniline dyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

disadvantage of using Xylene for more than 3 hours

A

makes tissue excessively hard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Odd One Out: Disadvantage of Xylene
A) Highly inflammable
B) Not suitable for nervous tissues
C) Expensive
D) Makes tissue hard if used over 3 hours

A

C) Expensive – Xylene is cheap.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

used as a substitute for Xylene and Benzene, and is less likely to make tissues hard and brittle

A

Toluene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

clearing time for Toluene

A

1-2 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Odd One Out: Advantage of Toluene
A) Miscible with alcohol and paraffin
B) Does not make tissues excessively hard
C) Slow clearing agent
D) Acts fairly rapidly for routine purposes

A

C) Slow clearing agent – Slower than xylene and benzene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F Toluene is slower than Xylene and Benzene, and it acidifies in a partially filled vessel.

A

T

28
Q

Odd One Out: Disadvantages of Toluene
A) Emits toxic fumes upon prolonged exposure
B) Acidifies in a partially filled vessel
C) Makes tissue brittle after 24 hours
D) More expensive

A

C) Makes tissue brittle after 24 hours – does not make tissues brittle after 24 hours.

29
Q

preferred by some in the
embedding process because it
penetrates and clears tissues
rapidly

A

Benzene

30
Q

clearing agent that volatilizes rapidly in a paraffin oven, does not make tissues hard and brittle, and causes minimum shrinkage

A

Benzene

31
Q

T/F Benzene is highly inflammable and may cause tissue shrinkage if left in benzene for a long time.

A

T

32
Q

Odd One Out: Advantage of Benzene
A) Rapid acting
B) Does not make tissues hard
C) Causes minimum shrinkage
D) Suitable for thicker tissue blocks

A

D) Suitable for thicker tissue blocks – Benzene is used for thinner tissue blocks.

33
Q

serious health risk associated with prolonged exposure to Benzene

A

extremely toxic to humans upon excessive exposure

34
Q

agent that when used for clearing in
embedding process, it’s slower than
xylene and causes less brittleness

A

Chloroform

34
Q

T/F Chloroform can be used for thicker tissue blocks (up to 1cm)

A

T

35
Q

clearing agent suitable for large tissue specimens, nervous tissues, and lymph nodes, and is not inflammable?

A

Chloroform

36
Q

Odd One Out: Disadvantage of Chloroform
A) Toxic to the liver
B) Tends to float tissues
C) Makes tissues transparent
D) Wax impregnation is slow after clearing

A

C) Makes tissues transparent – Chloroform does not make tissues transparent

37
Q

Odd One Out: Disadvantage of Chloroform
A) Complete clearing is difficult to evaluate
B) Evaporates quickly from a water bath
C) Wax impregnation is slow
D) Attacks rubber seals in vacuum baths

A

B) Evaporates quickly from a water bath – Chloroform evaporates slowly from a water bath.

38
Q

typical clearing time for Cedarwood Oil

A

2-3 days

39
Q

Odd One Out: Disadvantage of Cedarwood Oil
A) Becomes milky upon prolonged storage
B) Causes extensive tissue shrinkage
C) Hard to eliminate from tissues in paraffin bath
D) Expensive

A

B) Causes extensive tissue shrinkage – minimal shrinkage.

40
Q

T/F: Aniline Oil is commonly used in routine clearing for large tissue samples.

A

F - not used routinely

41
Q

Clearing agent that causes minimal tissue shrinkage but is unsuitable for routine clearing due to its tendency to adulterate and make tissues brittle

A

Clove Oil

42
Q

Odd One Out: Disadvantage of Clove Oil
A) Expensive
B) Causes tissues to become brittle
C) Removes aniline dyes
D) Makes tissues transparent

A

D) Makes tissues transparent – Clove Oil does not make tissues transparent.

43
Q

clearing agent that has properties similar to chloroform but produces considerable tissue hardening and is highly toxic

A

Carbon Tetrachloride

44
Q

T/F: Carbon Tetrachloride is associated with health hazards similar to chloroform, including toxicity upon prolonged exposure.

A

T

45
Q

what is double embedding, and why are Methyl Benzoate/Methyl Salicylate used for it

A

It uses two embedding media (e.g., celloidin and paraffin) and these agents are ideal because they act slowly.

46
Q

clearing agent that has the ability to perform both dehydration and clearing at the same time and is non-toxic but has an offensive odor

A

Tetrahydrofuran

47
Q

T/F: Tetrahydrofuran is toxic and should be handled with caution.

A

False – non-toxic, but has an offensive odor

48
Q

significant health risk associated with Dioxane

A

toxic to liver

49
Q

Odd One Out: Disadvantage of Dioxane
A) Causes greater shrinkage than xylene
B) Toxic to the liver
C) Fast-acting in embedding
D) Slow tissue impregnation

A

D) Slow tissue impregnation – fast because it allows tissues to be embedded within 4 hours

50
Q

done to xylene containers to prevent it from entering the atmosphere and sublimating

A

keep it tightly closed (wow ang oa)

51
Q
A
52
Q

T/F: Xylene should be stored in a flammable liquid storage cabinet, away from incompatible substances

A

T

52
Q

T/F: Coconut Oil is commonly used in the histopathological laboratory as a dealcoholization agent without compromising histological quality.

A

T

53
Q

Odd One Out: NOT a less-toxic substitute for xylene
A) Limonene reagents
B) Vegetable oils
C) Coconut oil
D) Alcohol

A

D) Alcohol – not a substitute for xylene

54
Q

offer the lowest hazard rating among xylene alternatives and preserve fine tissue structure.

A

ORANGE OIL BASED CLEARING AGENTS

54
Q

isoprene polymers found in essential oils originally derived from plants.

A

Terpenes

55
Q

Which of the following is NOT a source of terpenes that can be used as a clearing substitute?
A) Oil of bergamot
B) Cedarwood oil
C) Olive Oil
D) Oil of sandalwood

A

C) Olive Oil – not a terpene; panluto yn tanga

56
Q

oil considered as an efficient substitute for xylene due to being nonhazardous and less expensive

A

Coconut Oil

56
Q

volatile oil found in citrus peels, such as lemons and oranges

A

Limonene

57
Q

T/F Orange oil can often be used in place of xylene without altering the protocol.

A

T

57
Q

effective solvents but are considered toxic chemicals that pose serious health risks

A

Chlorinated Hydrocarbons

58
Q

Odd One Out: Which of the following is NOT an advantage of Coconut Oil?
A) Nonhazardous
B) Causes significant shrinkage
C) Less expensive
D) Good for dealcoholization

A

B) Causes significant shrinkage – Coconut Oil causes less shrinkage of tissue.

58
Q

provides good tissue sections and is non-toxic, nonhazardous, and nonflammable

A

Bleached Palm Oil

58
Q

T/F: Bleached Palm Oil is not biodegradable.

A

F - biodegradable.

59
Q

Odd One Out: Characteristic of Bleached Palm Oil
A) Easy to handle
B) Highly toxic
C) Economic
D) Readily available

A

B) Highly toxic – non-toxic.

[2S] HP LAB (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions