Decalcification

Question 1

what is decalcification

Answer 1

to remove minerals from bone or other calcified tissue

Question 2

effect of decalcification

Answer 2

hard cutting of tissuese

Question 3

effect of over-calcification

Answer 3

will hardly react to eosin

Question 4

calcium may be removed by one of the following agents, enumerate.

Answer 4

acids, chelating agents, ion exchange resins, electrical ionization

Question 5

enumerate the acid decalcifying agents

Answer 5

• nitric acid
• hydrochloric acid
• formic acid
• formic acid - sodium citrate solution
• trichloroactetic acid
• sulfurous acid
• chromic acid
• citric acid

Question 6

most common and fastest decalcifying agent

Answer 6

nitric acid

Question 7

aqueous nitric acid solution 10% components and decal time

Answer 7

concentrated nitric acid + distilled water
12-24 hours

Question 8

recommended for urgent biopsies, needle, and small biopsies

Answer 8

aqueous nitric acid solution 10%

Question 9

FORMOL-NITRIC ACID (10%) components and decalcification time

Answer 9

concentrated nitric acid + strong formaldehyde + distilled water
1-3 days

Question 10

component and decal time of perenyi’s fluid

Answer 10

10% nitric acid + 0.5% chromic acid + absolute ethyl alcohol
2-7 days

Question 11

phloroglucin nitric acid components and decal time

Answer 11

concentrated nitric acid + phloroglucin + 10% nitric acid
12-24 hours

Question 12

most rapid decalcifying agent

Answer 12

phloroglucin nitric acid

Question 13

enumerate the 4 decalcifying agents under NITRIC ACID

Answer 13

formol-nitric acid, aqueous nitric acid solution 10%, perenyi’s fluid, phloroglucin nitric acid

Question 14

inferior to nitric acid due to its lower action and greater distortion

Answer 14

hydrochloric acid

Question 15

give an example of a hydrochloric acid decalcifying agent

Answer 15

von ebner’s fluid

Question 16

von ebner’s fluid components

Answer 16

Saturated aqueous solution of 36% NaCl + conc. HCL _ distilled water

Question 17

this acid decalcifying agent recommended for teeth and small pieces of bones

Answer 17

von ebner’s fluid

Question 18

the only weak acid used extensively as primary decalcifying agent for decalcification of post-mortem tissues not for urgent exams

Answer 18

formic acid

Question 19

component and decalcification time of formic acid

Answer 19

formic acid + 10% formol saline
2-7 days

Question 20

components and decal time of formic acid - sodium citrate solution

Answer 20

20% aqueous sodium citrate + 45% formic acid
3-14 days

Question 21

recommended for autopsy materials, bone marrow cartilage, and tissue studied for research

Answer 21

formic acid - sodium citrate solution

Question 22

components and decal time of trichloroacetic acid

Answer 22

TCA + 10% formol saline
4-8 days

Question 23

weak decalcifying solution suitable only for minute pieces of bone

Answer 23

sulfurous acid

Question 24

chromic acid (flemming’s solution) components

Answer 24

chromic acid + osmium tetroxide + glacial acetic acid

Question 25

citric acid - citrate buffer solution pH, component, and decal time

Answer 25

4.5 7% citric acid monohydrate aqueous solution + 7.4% ammonium citrate (anhydrous) aqueous solution + 1% zinc sulfate aqueous solution + few drops of chloroform 6 days

Question 26

most common chelating agent

Answer 26

EDTA

Question 27

substances which combine calcium ions and other salts

Answer 27

chelating agents

Question 28

commercial name of edta

Answer 28

versene and sequestrene

Question 29

ion exchange resin is an ammonium form of __

Answer 29

polystyrene resin

Question 30

removes calcium ions from formic acid thereby increasing solubility from the tissue

Answer 30

ion exchange resin

Question 31

ion exchange resin is not recommended for fluids containing mineral acids such as __

Answer 31

nitric or hydrochloric acid

Question 32

process whereby positively charged calcium ions are attached to a negative electrode and subsequently remove from the decalcifying agent

Answer 32

electrophoresis

Question 33

solutions used in electrophoresis

Answer 33

88% formic acid, concentrated HCl, distilled water

Question 34

enumerate the 3 ways to measure the extent of decalcification

Answer 34

physical or mechanical method, xray/radiological, chemical/calcium oxalate test

Question 35

most ideal, most sensitive, most reliable method which is not recommended for mercuric chloride-fixed itssues

Answer 35

xray/radiological

Question 36

reliable, convenient method recommended for routine purposes and the decalcifying fluid is changed every 24-48 hrs

Answer 36

chemical method/calcium oxalate test

Question 37

solutions used in calcium oxalate test

Answer 37

concentrated ammonium hydroxide, saturated aqueous ammonium oxalate

Question 38

presence of cloudiness in chemical method indicates?

Answer 38

presence of Ca (incomplete decalcification)