Histo Sem W2: Decalcification

decalcification

done to soften tissue by removal of calcium or lime salts

decalcification

best performed after fixation and before dehydration

20x

volume of decalcification

nitric acid

most common; fastest

aqueous nitric acid

commonly used

perenyi’s

decalcifies and softens tissue

von ebner’s fluid

teeth, small pieces of bone

formic acid

post-mortem research

chromic acid

inhibits nuclear staining

sulfurous acid

very weak decalcifying

physical

not recommended

chemical

most commonly used

cloudiness

incomplete decalcification

radiologic

most ideal

edta

use of chelating agents

1 to 3 weeks

weeks for small specimens

6 to 8 weeks

weeks for dense tissues

ion exchange resin

remove calcium ions from formic acid-containing decalcifying solutions, thereby increasing solubility from the tissue

electrophoresis

positively charged calcium ions are attracted to a negative electrode and subsequently removed from decalcifying solution

tissue softeners

Perenyi’s fluid

4% aqueous phenol

Molliflex

2% HCl
1% HCl in 70% alcohol