Decalcification

Question 1

Decalcifying agents

Answer 1

1) Acids
2) Chelating agents
3) Ion exchange resins
4) Electrical ionization/electrophoresis

Question 2

Most common and fastest; for routine purposes; undergo spontaneous yellow discoloration

Answer 2

Nitric acid

Question 3

Urgent biopsies; needle and small biopsies; large cortical bone

Answer 3

10% aqueous nitric acid

Question 4

Less tissue destruction than 10% aq NA; for urgent biopsies w/ good nuclear staining; used inside a fume hood

Answer 4

Formol-Nitric acid

Question 5

Routine purposes; decalcify and soften; maceration is avoided

Answer 5

Perenyi’s fluid

Question 6

Most rapid decal agent; poor nuclear staining; yellow color formation

Answer 6

Phloroglucin Nitric acid

Question 7

Inferior to nitric acid; good nuclear staining; for surface decal

Answer 7

HCl/muriatic acid

Question 8

For teeth and small pieces of bone

Answer 8

Von Ebner’s fluid

Question 9

Moderate-acting; for post-mortem research tissues

Answer 9

Formic acid

Question 10

For small pieces of bone and teeth; suitable for most routine surgical specimen and immunohistochemical staining

Answer 10

Aqueous formic acid

Question 11

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

Answer 11

Formic acid-Sodium citrate

Question 12

Does not require washing out; not recommended for urgent exams

Answer 12

Trichloroacetic acid

Question 13

Weakest decal agent; only for minute pieces of bone

Answer 13

Sulfurous acid

Question 14

Fixative and decalcifying agent; environmental toxin; highly corrosive; carcinogenic

Answer 14

Chromic acid

Question 15

Does not produce cell or tissue distortion

Answer 15

Citric acid-Citrate buffer

Question 16

Combine with calcium ions and other salts to form complexes and facilitate removal of calcium salt

Answer 16

Chelating agents

Question 17

Most common chelating agent

Answer 17

EDTA

Question 18

Used as anticoagulant, decal agent, and water softener

Answer 18

EDTA

Question 19

Commercial names of EDTA

Answer 19

1) Versene (Na2 EDTA)
2) Sequestrene (K3 EDTA)

Question 20

Hastens decal by removing calcium ions from formic acid, thereby increasing solubility from tissue;

Not recommended for fluids containing mineral acids, such as nitric or hydrochloric acids

Answer 20

Ion-exchange resin

Question 21

Process where calcium ions (+) are attracted to the cathode (-) and subsequently remived from the decalcifying solution

This process utilizes electricity and depends on direct current to remove calcium deposits

Answer 21

Electrical ionization/Electrophoresis

Question 22

Solutions used in electrophoresis

Answer 22

1) 88% formic acid
2) conc. HCL
3) DW

Question 23

A way to measure the extent of decal by touching the tissue or by picking it with a fine needle

Answer 23

Physical/Mechanical method

Question 24

A way to measure the extent of decal that is very expensive, most, ideal, most sensitive, and most reliable

Not recommended for mercuric-chloride fized tissues

Answer 24

X-ray/Radiologic method

Question 25

A way to measure the extent of decal that is simple, reliable, convenient; recommended for routine purposes

Decal fluid is replaced every 24-48 hrs

Detect calcium in acid solutions by ppt of insoluble calcium hydroxide/oxalate

Cloudiness = Ca2+ is present (incomplete decal)

Answer 25

Chemical/Calcium Oxalate method

Question 26

Solutions used in Calcium Oxalate Test

Answer 26

1) conc. ammonium hydroxide
2) saturated aq. ammonium oxalate

Question 27

Tissue softeners

Answer 27

1) perenyi
2) 4% phenol
3) molliflex
4) 2% hcl
5) 1% hcl in 70% alcohol