Decalcification-Clearing

Question 1

The most common chelating agent

Answer 1

EDTA with pH 7

Question 2

The most common decalcifying agent

Answer 2

Nitric acid

Question 3

It is both a tissue softener and a decalcifying agent

Answer 3

Perenyi’s fluid

Question 4

It is the most rapid decalcifying agent; overall better than nitric acid

Answer 4

Phloroglucinol-Nitric acid

Question 5

It is good for nuclear staining

Answer 5

Trichloroacetic acid (TCA)

Question 6

Both fixative and a decalcifying agent

Answer 6

Formic acid
Chromic acid or Flemming’s fluid

Question 7

How long is the decalcification time using nitric acid

Answer 7

12-24 hours

Question 8

Composition of Phloroglucinol-Nitric acid

Answer 8

10 mL concentrated nitric acid
1 g phloroglucin
100 mL 10% nitric acid

Question 9

Composition of Perenyi’s fluid

Answer 9

40 mL 10% nitric acid
30 mL 0.5% chromic acid
30 mL absolute ethanol

Question 10

Comparison of nitric acid and phloroglucinol nitric acid

Answer 10

Nitric acid is good for nuclear staining while the latter is not

Question 11

These decalcifying agents don’t require washing

Answer 11

Von Ebner’s fluid,
TCA

Question 12

Used for minute bone spicules

Answer 12

Chromic acid

Question 13

Decalcifying agents that permit good nuclear and cytoplasmic staining

Answer 13

Formic acid
Trichloroacetic acid (TCA)
Citric acid-citrate buffer solution

Question 14

Require neutralization with 5% sodium sulfate

Answer 14

Phloroglucinol-Nitric acid,
Formic acid

Question 15

What is the ideal decalcification time

Answer 15

24-48 hours

Question 16

What is the optimum temperature for decalcification

Answer 16

18-30 deg C

Question 17

Dense bone tissue require up to _____ weeks to complete decalcification process.

Answer 17

14 days

Question 18

What is the preferred method of measuring the extent of calcification

Answer 18

Chemical method/calcium oxalate method

Question 19

Most widely used dehydrating agent

Answer 19

Ethanol

Question 20

A dehydrating agent that does not dissolve nitrocellulose

Answer 20

Methanol

Question 21

Superior lipid solvent

Answer 21

isopropanol

Question 22

It cannot be used for celloidin embedding

Answer 22

Isopropanol

Question 23

For rapid dehydration of 1 hour

Answer 23

Acetone

Question 24

It is both a dehydrating and clearing agent

Answer 24

Dioxane

Question 25

True or False Long, slow dehydration gives the best results

Answer 25

True

Question 26

Also known as dealcoholization

Answer 26

Clearing

Question 27

it is the process of replacing the dehydrating fluid with a fluid that is miscible with both the dehydrating fluid and the impregnating/embedding medium

Answer 27

Clearing

Question 28

Ideal Characteristics of a Clearing Agent

Answer 28

1. Should be miscible with alcohol to promote rapid removal of the dehydrating agent 2. Should be miscible and easily removed by melted paraffin wax and/or by mounting medium to facilitate impregnation and mounting sections. 3. Should not produce excessive shrinkage, hardening, or damage of tissue 4. Should not dissolve aniline dyes 5. Should not evaporate quickly +. However, clearing agent should evaporate quickly inside the oven. 6. Should make the tissues transparent.

Question 29

Colorless and mostly used clearing agent

Answer 29

Xylene

Question 30

The most rapid clearing agent 15-30 mins

Answer 30

Xylene

Question 31

What is the remedy when Xylene becomes milky due to incomplete dehydration

Answer 31

Immersion of the tissue in absolute alcohol (rehydration)

Question 32

A substitute for Xylene and Benzene

Answer 32

Toluene

Question 33

A clearing agent recommended for tough tissues like skin, fibroid, and decalcified tissues; nervous, lymph nodes, and embryos

Answer 33

Chloroform

Question 34

A disadvantage of chloroform

Answer 34

it does not make the tissue transparent

Question 35

Slow-acting clearing agents that can be used when double-embedding techniques are required

Answer 35

Methyl benzoate and Methyl salicylate

Question 36

It is an expensive clearing agent used to clear both paraffin and celloidin sections during embedding process; Recommended for CNS tissues and cytological studies

Answer 36

Cedarwood oil

Question 37

Rapid acting but causes brittle and hard tissue; Causes aplastic anemia

Answer 37

Benzene

Question 38

Recommended for embryos, insects, and very delicate specimens

Answer 38

Aniline oil

Question 39

Clearing agents suitable for CNS

Answer 39

Chloroform,Cedarwood oil

Question 40

Clearing agents suitable for embryos

Answer 40

Chloroform, Aniline oil