Decalcification Flashcards
Step in tissue processing that involves removal of calcium
Decalcification
T/F: Not all specimens will undergo decalcification because it is not a routine step
TRUE
What is the main purpose of decalcification?
Soften hard tissue to facilitate easy cutting
Example of tissue softener used when the tissue is still hard after decalcification
Molliflex-Pereyni’s
Time required for decalcification
24 to 48 hours
Temperature range for decalcification
18-30degC (room temp)
Ratio of decalcification agent to tissue volume
20:1
Factors that affect the decalcification time
- Degree of mineralization
- Concentration and volume of the decalcifying agent
- Heating & agitation
If calcium content is high or heavy-mineralized, decalcification rate will be
Longer
If a specimen is bone from an osteoporotic patient, it will have low calcium content the decalcification rate will be
Shorter
Increasing the concentration and volume of the decalcifying agent
The longer the decalcification time
Most commonly used method of decalcification
Use of Acids
Method of decalcification that uses EDTA
Use of chelating agent
Method of decalcification that is not suited for urgent biopsies
Ion Exchange Resin
Duration of decalcification thru ion exchange resin
1-14 days
Most reliable and accurate method of testing used to measure the extent of decalcification
Can detect the smallest calcium
Xray/Radiologic
Done by bending the tissue, probing or pricking the tissue with needle
Mechanical/Physical
Method of testing for the completeness of decalcification that uses calcium carbonate
Bubble Test
If after adding CaCO3 > present of tiny bubbles > specimen is not yet calcified > what is the next step?
Extend decalcificaiton
Uses 5mL or 0.5mL decalcifying agent (acidic in nature) + strong ammonia > alkaline
Chemical method
In chemical method, if the result is turbid, the decalcification is not yet _
Complete
- Most potent anticoagulant but weak decalcifying agent
- Binds with calcium to form weakly dissociated complexes
- An excellent bone decalcifier for EM and Enzyme histochemistry
EDTA
Disadvantage of EDTA
It can inactivate alkaline phosphatase
Remmedy for inactivation of alkaline phosphatase by EDTA
Magnesium chloride
