Decalcifying Reagents

Question 1

Tissue to decalcifying agent volume

Answer 1

20 x

Question 2

Decalcifying agents

Answer 2

A C I E

Acids
Chelsting agent
Ion exchange resin
Electrical ionization/Electrophoresis

Question 3

Factors influencing rate of decalcification

Answer 3

STC
Structure
Ttemperature
Concentration and volume

Question 4

The only decalcifying agent used for routine purpose

Answer 4

acids
(Because calcium is soluble @4.5 pH)

Question 5

Almost 2x as fast as formic axid

Answer 5

Nitric acid

Question 6

Provides better tissue and cellular preservation and staining

Answer 6

Formic acid

Question 7

Cid decalcifying agents

Answer 7

1. Nitric acid
   - 10% aqueous Nitric acid
   - Formol Nitric acid
   - Perenyi’s fluid
   - Phloroglucin Nitric acid
2. Hydrochloric acid/Muriatic acid
3. Formic acid
4. Trichloroacetic acid
5. Sulfurous acid
6. Chromic acid
7. Citric acid buffer

Question 8

Most common and fastest decal agent

Answer 8

Nitric acid

Question 9

Undergoes spontaneous yellow discoloration owing to formation of Nitrous acid

Answer 9

Nitric acid

Question 10

Rapid
For URGENT BIOPSIES, NEEDLE and SMALL specimen biopsies

Answer 10

10% Aqueous Nitric acid

Question 11

Used for heavily or large mineralized cortical bone specimen

Decal time is 12 to 24 hours

Answer 11

10% Aqueous Nitric acid

Question 12

Less tissue destruction than 10% Aqueous Nitric acid

Decal time is 1 to 3 says

Answer 12

Formol Nitric acid

Question 13

Recommended concentration of nitric acid

Answer 13

5 to 10 %

Question 14

For URGENT biopsies with good nuclear staining

Answer 14

Formol Nitric acid

Question 15

Decalcification time of Formol Nitric acid decal agent

Answer 15

1-3 days

Question 16

Yellow color imparted by nitrous acid is removed through:

Answer 16

Neutralization with 5% SPDIUM SULFATE and running tap water for 12 hours ( or addition of 1% urea to pure concentrated nitric acid)

Question 17

Decalcification time of Perenyi’s fluid

Answer 17

2-7 days

Question 18

It decalcifies and softens at the same time

Answer 18

Perenyi’s fluid

Question 19

Maceration is avoided due to the presence of chromic acid and alcohol (ethanol)

Answer 19

Perenyi’s fluid

*(Maceration is the softening and breaking down of tissues)

Question 20

Composition of Perenyi’s fluid

Answer 20

Nitric acid • Chromic acid • Ethanol

Question 21

Most rapid decalcifying agent but has poor nuclear staining

Answer 21

Phloroglucin Nitric acid

Question 22

Decal time of Phloroglucin Nitric acid

Answer 22

12-24 hours

Question 23

Recommended for urgent works and produces a yellow color formation

Answer 23

Phloroglucin Nitric acid

Question 24

Inferior compared to nitric acid (slower action and greater destruction of tissues)

Answer 24

HCl or Muriatic acid

Question 25

Recommended for **surface decalcification** of tissue blocks if used in 1% sol'n with 70% alcohol Good nuclear staining

Answer 25

HXl or Muriatic acid

Question 26

Recommended for teeth and small pieces of bones

Answer 26

Von ebner's fluid

Question 27

Von ebner's fluid decomposition

Answer 27

**36% saturated aqueous solution sodium chloride** **Concentrated HCl** **Distilled water**

Question 28

Decal time of formic acid

Answer 28

2-7 days

Question 29

Moderate- acting decalcifying agent Recommended for routine decalcification of **post-mortem research tissues**

Answer 29

Formic acid

Question 30

Major disadvantage is not suitable for decalcifying urgent Exam

Answer 30

Formic acid

Question 31

Formic acid + 10% Formol saline

Answer 31

Aqueous formic acid

Question 32

Recommended for small pieces of bones and teeth; Suitable for most routine surgical specimen and immunohistochemical staining

Answer 32

Aqueous formic acid

Question 33

Formic acid-Sodium citrate decomposition

Answer 33

20% Aq. Sodium citrate + 45% Formic acid

Question 34

Recommended for autopsy materials, bone marrow, cartilage and tissues studied for research purposes

Answer 34

Formic acid-Sodium citrate

Question 35

Permits good nuclear staining; Does not require washing out Not recommended for urgent examinations (very slow acting

Answer 35

Trichloroacetic acid

Question 36

Weakest decalcifying agent, suitable only for minute pieces of bone

Answer 36

Sulfurous acid

Question 37

Used as a fixative and decalcifying agent; Decalcifies minute bone spicules Caution: It is an environmental toxin, highly corrosive to skin and mucous membrane and carcinogenic

Answer 37

Chromic acid

Question 38

Permits excellent nuclear and cytoplasmic staining Does not produce cell or tissue distortion; Too slow for routine purposes

Answer 38

Citric acid Citrate buffer

Question 39

Substances which combine with calcium ions and other salts IRON and MAGNESIUM to form weakly dissociated complexes and facilitate removal of Calcium salt

Answer 39

Chelating agent