Decalcification Flashcards
Removal of calcium and lime salts
Decalcification
Done after fixation and before dehydraation and impregnation
Decalcification
Calcium might interfere with accurate evaluation and examination
Decalcification
Facilitate normal cutting of tissue in sectioning
prevent obscuring microanatomical detail of
tissue
Decalcification
Organs that requires decalcification
- Bones - because calcium is present in bones
- Tuberculous lungs - calcified lungs because of
TB bacteria - Atherosclerotic vessels - lipids, calcium,
cellular debris in the lumen of blood vessels - Teeth
FACTORS AFFECTING THE RATE OF
DECALCIFICATION
- Concentration
○ If less concentrated, slow-acting - Tissue-to-volume ratio
○ 1:20 (tissue:decalcifying agent or
solution) - Temperature
○ Must be regulated - Mechanical agitation
○ Key to a rapid decalcifying of sample - Size and consistency of tissue sample
○ If sample is thick and rigid, longer
decalcifying time
Four types of decalcifying agents
- Acid
- Chelating agents
- Ion Exchange resin
- Electrophoresis
Routine or most common decalcifying agent
Nitric acid (5-10%)
Imparts yellow coloration d/t nitrous acid formation
Nitric acid (5-10%)
also acts as tissue
softener; Nitric acid + Chromic acid +
ROH
Perenyi’s fluid
Fastest agent (simple or compound) 5-10%
Phloroglucin Nitric acid
Provides good nuclear staining at 1%
Hydrochloric acid
Slower and causes more distortion compared to HNO3
Hydrochloric acid
For teeth and small bones
Von Ebner’s fluid
HCI + 36% NaCH + distilled water
Von Ebner’s fluid
For routine decalcification of post-morten research tissues, small pieces of bone and teeth
Formic acid
Tissue sample is from human who is already deceased
Post-mortem
Good for in situ hybridization staining
Formic acid
is better than HNO3
Formic acid - sodium citrate solution
Small bone spicules
Trichloroacetic acid
Good nuclear staining
Trichloroacetic acid
Minute pieces of bone
Sulfuruous acid
Minute bone spicules
Chromic acid (flemming’s fluid)
Use of salts to form complexes with catt salets for ease of removal
Cheating agents
