STEP 2: DEHYDRATION

Question 1

process of removing intercellular and extracellular water from the tissues

Answer 1

dehydration

Question 2

dehydration involves ________ concentration of alcohol

Answer 2

increasing

starts by 70% ethyl alcohol in water to 95% ethyl alcohol to 100% ethyl alcohol

Question 3

volume of dehydrating fluid

Answer 3

must not be less than 10 time the volume of the tissue

Question 4

at 37C will hasten dehydration time for tissue sections that require urgent examination

Answer 4

alcohol

Question 5

ensures complete dehydration

Answer 5

anhydrous copper sulfate

Question 6

results that indicate full saturation of dehydrating fluid with water

Answer 6

blue discoloration of copper sulfate crystals

Question 7

recommended for routine dehydration of tissues

Answer 7

ethyl alcohol

Question 8

best dehydrating agent

Answer 8

ethyl alcohol

Question 9

toxic dehydrating agent

Answer 9

methyl alcohol
cellusolve (toxic by inhalation, skin contact and ingestion)
tetrahydrofuran (toxic if ingested or inhaled)

Question 10

dehydrating agent used for blood and tissue films, and smear preparations

Answer 10

methyl alcohol

Question 11

dehydrating agent used in plant and animal micro-techniques

Answer 11

butyl alcohol

Question 12

slow dehydrating agent; for tissues which do not require rapid processing

Answer 12

butyl alcohol

Question 13

produce less shrinkage and hardening than ethanol

Answer 13

butyl alcohol

Question 14

rapid acting dehydrating agents

Answer 14

acetone

Question 15

for most urgent biopsies

Answer 15

acetone

Question 16

dehydrating agent used for most urgent biopsies

Answer 16

acetone

Question 17

dehydrating agent the removes most lipids from tissues

Answer 17

acetone

Question 18

dehydrating agent limited only to small pieces of tissues; not recommended for routine dehydration

Answer 18

acetone

Question 19

excellent dehydrating and clearing agent

Answer 19

dioxane

Question 20

tissues can be left in this dehydrating agent for long periods of time without affecting the consistency or staining properties but dehydrated sections tend to ribbon poorly

Answer 20

dioxane

Question 21

what is Weiseberger’s method?

Answer 21

a dehydration technique where the tissue is wrapped in a gauze bag and suspended in a bottle containing dioxane and a little anhydrous calcium oxide (or quicklime)

Question 22

the tissue may be transferred from water or normal saline directly to this dehydrating agent and stored in it for months without producing hardening or distortion

Answer 22

cellosolve

Question 23

disadvantage: combustible at 110-120F, toxic by inhalation, skin contact and ingestion

Answer 23

cellosolve

Question 24

alternative for cellosolve

Answer 24

Propylene-based glycol ethers

Question 25

other name for cellosolve

Answer 25

ethylene glycol monoethyl ether

Question 26

other name for dioxane

Answer 26

diethylene dioxide

Question 27

used to dehydrate sections and smears following certain stains. it is soluble in alcohol, water, ether, benzene, chloroform, acetone, xylene

Answer 27

triethyl phosphate

Question 28

may be used for demixing, clearing and dehydrating paraffin sections before and after staining

Answer 28

tetrahydrofuran (THF)

Question 29

dehydrating agent that does not dissolve out aniline dyes

Answer 29

tetrahydrofuran (THF)

Question 30

dehydration additive used as a tissue softener for hard tissues such as tendon, nail, or dense fibrous tissue

Answer 30

4% phenol

Question 31

additives for dehydration

Answer 31

4% phenol
glycerol/alcohol mixture
molliflex