HISTOPATH (DEHY-DECAL)

Question 1

is the removal of calcium ions (Ca2+)
from a bone or calcified tissue through a histological
process in order to make them flexible and easier to
cut

Answer 1

Decalcification

Question 2

Principle of Decalcification

Answer 2

Form soluble calcium salts in an ion exchange that moves calcium into the decalcifying solution

Question 3

Higher concentration of decalcifier = _________________

Answer 3

Faster Decalcification

Question 4

Higher temperature during decalcification = _________________

Answer 4

Increased rate of Decalcification

Question 5

Fluid to tissue ratio during Decalcification

Answer 5

20:1

Question 6

Compound found in bones

Answer 6

Ca10(PO4)6(OH)2
Hydroxyapatite

Question 7

Byproduct of decalcification reaction

Answer 7

6 H2PO4

Question 8

3 Main types of Decalcifying agents

Answer 8

Strong Mineral Acids
Weak Organic Acids
Chelating Agents

Question 9

37 deg C during decalcification = ____________

Answer 9

impaired nuclear staining of Von Gieson’s

Question 10

55 deg C during decalcification = ____________

Answer 10

tissue will undergo complete digestion within 24 hours

Question 11

Ideal time of decalcification

Answer 11

24-48 hours

Question 12

Types of Decalcifiers

Answer 12

ACIDS
CHELATING AGENTS
ELECTRIC IONIZATION

Question 13

Most widely used Type of Decalcifiers

Answer 13

ACIDS

Question 14

Type of Decalcifiers that involves the Exchanging particular ions
within the polymer.
Utilizes EDTA.

Answer 14

CHELATING AGENTS

Question 15

Ions move across a gel
membrane, leaving the
tissue, as they are repelled by like charges from electrodes.

Answer 15

Electrophoresis

Question 16

● Moderate acting
● Fixate and decalcify
● For post-mortem tissues
● For excellent nuclear cytoplasmic staining
● For small pieces of bones and teeth

Answer 16

FORMIC ACID

Question 17

For autopsy materials, bone marrow, cartilage, and tissues are studied for research purposes.

Answer 17

FORMIC ACID - SODIUM CITRATE

Question 18

● Inferior to Nitric Acid but produces good staining.
● Slower action and greater distortion to tissue.

Answer 18

HYDROCHLORIC ACID

Question 18

● Does not require washing out before dehydration.
● For teeth and small pieces of bone.

Answer 18

VON EBNER’S FLUID

Question 19

Composition of VON EBNER’S FLUID

Answer 19

(HCI + NaCl + H2O)

Question 20

● Good nuclear staining
● Does not require washing out
● Not recommended for urgent examinations (very slow acting)

Answer 20

TRICHLOROACETIC ACID

Question 21

● Fixative and decalcifying agent
● For minute bone spicules

Answer 21

CHROMIC ACID (FLEMMING’S FLUID)

Question 22

● Most common, very rapid.
● Good nuclear stain.
● Easily removed by 70% alcohol (R-OH).

Answer 22

NITRIC ACID

Question 23

NITRIC ACID is easily removed by _______

Answer 23

70% Alcohol

Question 24

Factors that Influence Decalcification

Answer 24

- Concentration - Fluid Access - Size and Consistency - Agitation - Temperature

Question 25

● Affect the rate at which Calcium is removed. ● Concentrated acid solutions decalcify more rapidly, but are more harmful to the tissue.

Answer 25

CONCENTRATION

Question 26

● Ready access to all surfaces of the specimen. ● Enhance diffusion and penetration into the specimen if suspected.

Answer 26

FLUID ACCESS

Question 27

● Increase in ____________________ of tissues will require longer periods for complete decalcification. ● Require up to 14 days or longer

Answer 27

SIZE AND CONSISTENCY

Question 28

________________ may increase the rate of Decalcification

Answer 28

Gentle agitation

Question 29

● Increased ___________ will hasten decalcification, but it will also increase the damaging effects of acids on tissue

Answer 29

temperature

Question 30

Optimum temperature for Decalcification

Answer 30

18-30 deg C

Question 31

MEANS OF MEASURING THE EXTENT OF DECALCIFICATION

Answer 31

- Physical/ Mechanical (Needle Test) - Radiologic - Chemical

Question 32

MEANS OF MEASURING THE EXTENT OF DECALCIFICATION: ● a. Inaccurate, vague ● Tissue is pierced with a needle to determine consistency (firm/smooth).

Answer 32

- Physical/ Mechanical (Needle Test)

Question 33

MEANS OF MEASURING THE EXTENT OF DECALCIFICATION: ● Most accurate/sensitive but expensive

Answer 33

- Radiologic

Question 34

In Radiologic: ● X-Ray film is used - ____________________ = Ca deposits

Answer 34

white discoloration

Question 35

MEANS OF MEASURING THE EXTENT OF DECALCIFICATION: ● Highly recommended ○ Use a litmus paper, ammonia water, & ammonium oxalate.

Answer 35

Chemical

Question 36

Expected result of Chemical Test

Answer 36

red/ acidic

Question 37

These substances are not strictly decalcifying agents, but they have mechanisms that contribute to make the tissue softer.

Answer 37

TISSUE SOFTENERS

Question 38

Examples of TISSUE SOFTENERS

Answer 38

1. 4% Aqueous Phenol 2. Molliflex 3. 2% Hydrochloric acid 4. 1% Hydrochloric acid in 70% alcohol 5. Perenyi's Fluid

Question 39

Tissue softener that takes 1-3 days in action

Answer 39

4% Aqueous Phenol

Question 40

Tissue softener that results to tissues appearing swollen and soapy

Answer 40

Molliflex

Question 41

Tissue softener that is a decalcifying agent at the same time

Answer 41

Perenyi's Fluid

Question 42

is the process of removing fixative and water from tissue

Answer 42

Dehydration or Desiccation

Question 43

Volume for Dehydration

Answer 43

Not less than 10x the Specimen

Question 44

Most common Dehydrant

Answer 44

Alcohol

Question 45

Tissues are exposed to increasing grades of concentration: _______________________

Answer 45

70% to 95% to 100%.

Question 46

For delicate tissues, particularly embryonic, starting with ________________ is recommended.

Answer 46

30% EtOH

Question 47

_______________________ tend to harden only the surface of the tissue while the deeper parts are not completely penetrated.

Answer 47

Concentrated alcohols 95% or absolute (~100%)

Question 48

Rapid acting dehydrant (0.5-2hrs)

Answer 48

Acetone

Question 49

Dehydrates and clears the specimen

Answer 49

- Tetrahydrofuran - Triethyl Phosphate

Question 50

Ethylene glycol Monoethyl Ether is also known as _______________

Answer 50

Cellusolve

Question 51

Universal Solvent but toxic

Answer 51

Diethylene Dioxide (DIOXANE)

Question 52

After fixation, the tissue is subjected to dehydration. To avoid contamination of the dehydrant, it may be necessary to change ______________________-

Answer 52

gauze wrapping