Decalci

Question 1

DECALFIFYING AGENTS

Types

Answer 1

Two Types:
Acid decalcifiers
Chelating agents

Question 2

STRONG (INORGANIC) ACIDS

Answer 2

Nitric acid, hydrochloric acid

Question 3

May be used as simple aquaeous solutions with concentrations of 5-10%
Decalcifying quickly causes tissue swelling and damage tissue stainability if used longer than 24-48H

Answer 3

STRONG (INORGANIC) ACIDS

Question 4

CHELATING AGENTS
EDTA will not bind to calcium at pH _

Optimal EDTA pH

Time of decalcification:

Answer 4

<3.0
Optimal EDTA pH = 7.0 to 7.4

Good for immunohistochemical stains and electron microscopy

Time of decalcification: 6-8 weeks

Question 5

Done either by:
Specimen radiography
Chemical methods to test acid and EDTA saturation
Weight loss-Weight gain procedures

Answer 5

DECALCIFICATION END POINT TEST

Question 6

Detection of calcium in acid solution by precipitation of insoluble _ or _ but is unsuitable for solutions containing over 10% acid even though this could be diluted and result in a less sensitive test.

Solutions:
_
_

Answer 6

CALCIUM OXALATE TEST
calcium hydroxide or calcium oxalate

Conc ammonium hydroxide
Sat aqueous ammonium oxalate

Question 7

Needed when partially decalcified bone or unsuspected mineral deposits in soft tissue are found in paraffin embedded tissues.

Answer 7

SURFACE DECALCIFICATION

1% HCl, 10% formic acid