Decalcifying Methods

Question 1

MOST COMMONLY USED acids

Answer 1

Nitric acid

usually 5-10% nitric acid room temperature

Question 2

Fast acting imparts a yellow color due to the formation of nitrous acid

Answer 2

Nitric acid

Question 3

Nitric acid Remedy wash

Answer 3

5% sodium thiosulfate

Question 4

Prevention add ________ ? before adding nitric acid

Answer 4

urea crystals

Question 5

For large heavily mineralized cortical bones duration 12-24 hours

Answer 5

10% Aqueous Nitric Acid

Question 6

40% Formaldehyde concentrated Nitric acid duration 1-3 days both a decalcifying agent and a tissue softener

Answer 6

Formol Nitric

Question 8

MOST RAPID positively charged calcium ions are attracted to negative electrodes

Answer 8

Electric ionization

Question 9

By electric current calcium is removed dependent upon the supply of electric current

Answer 9

Electric ionization

Question 10

For small bone fragments

Answer 10

Electric ionization

Question 11

Placed in distilled water with formic acid and HCl

Answer 11

Electric ionization

Question 12

Uses ammonium form of polystyrene resin placed on the bottom with formic acid

Answer 12

Ion exchange resin

Question 13

Calcium is rapidly removed increasing solubility from tissues

Answer 13

Ion exchange resin

Question 14

Amount of formic acid is 20-30x the volume of the tissue

Answer 14

Ion exchange resin

Question 15

Duration 14 days not suited for urgent biopsies

Answer 15

Ion exchange resin

Question 16

Binds with calcium to form weakly dissociated complexes thus facilitating calcium removal

Answer 16

Chelating agents

Question 17

Commonly used EDTA

Answer 17

Chelating agents

Question 18

Weak decalcifying agent not fast-acting expensive solution needs to be changed every 3 days inactivates ALP activity

Answer 18

Chelating agents

Question 19

Excellent bone decalcifier for immunohistochemical or enzyme staining and for EM

Answer 19

Chelating agents

Question 20

Inactivates alkaline phosphatase activity

Answer 20

Chelating agents

remedy addition of MgCl2

Question 21

For small specimens 1-3 weeks

Answer 21

Chelating agents

Question 22

Chelating agents For dense tissue

Du

Answer 22

6-8 weeks

Question 23

MOST COMMONLY USED routine concentrated solutions are not used

Answer 23

Use of acids

Question 24

Nitric Acid HCl

Answer 24

Strong acids

Question 25

Formic acid TCA Sulfurous acid Citric acid Chromic acid

Answer 25

Weak acids

Question 26

5-10% Nitric Acid routine fast acting imparts yellow color

Answer 26

Nitric acid

Question 27

Concentrated HCl distilled water 5-10% HCl inferior as compared to nitric

Answer 27

Hydrochloric acid

Question 28

For surface decalcification of blocks

Answer 28

Hydrochloric acid

Question 29

For teeth and small pieces of bone

Answer 29

Von Ebner’s

Question 30

Concentrated HCl NaCl NSS

Answer 30

Von Ebner’s

Question 31

Not routinely used can be used by itself or with sodium citrate

Answer 31

Formic acid

Question 32

Used as both a fixative and a decalcifying agent

Answer 32

Formic acid

Question 33

Safe to handle than nitric acid but slow-acting

Answer 33

Formic acid

Question 34

For routine decalcification of post-mortem tissues

Answer 34

Formic acid

Question 35

For cartilage autopsy bone marrow and research specimens

Answer 35

Formic acid sodium citrate

Question 36

Weak and slow acting agents

Answer 36

TCA Sulfurous acid Citric acid citrate buffer

Question 37

Can act as both a fixative and decalcifying agent

Answer 37

Chromic acid and formic acid

Question 38

Not routinely used environmental toxin highly corrosive to the skin and mucous membranes

Answer 38

Chromic acid

Question 39

Used only for minute pieces of bones

Answer 39

Chromic acid