Decalcification

Question 1

Step in tissue processing that involves removal of calcium

Answer 1

Decalcification

Question 2

T/F: Not all specimens will undergo decalcification because it is not a routine step

Answer 2

TRUE

Question 3

What is the main purpose of decalcification?

Answer 3

Soften hard tissue to facilitate easy cutting

Question 4

Example of tissue softener used when the tissue is still hard after decalcification

Answer 4

Molliflex-Pereyni’s

Question 5

Time required for decalcification

Answer 5

24 to 48 hours

Question 6

Temperature range for decalcification

Answer 6

18-30degC (room temp)

Question 7

Ratio of decalcification agent to tissue volume

Answer 7

20:1

Question 8

Factors that affect the decalcification time

Answer 8

• Degree of mineralization
• Concentration and volume of the decalcifying agent
• Heating & agitation

Question 9

If calcium content is high or heavy-mineralized, decalcification rate will be

Answer 9

Longer

Question 10

If a specimen is bone from an osteoporotic patient, it will have low calcium content the decalcification rate will be

Answer 10

Shorter

Question 11

Increasing the concentration and volume of the decalcifying agent

Answer 11

The longer the decalcification time

Question 12

Most commonly used method of decalcification

Answer 12

Use of Acids

Question 13

Method of decalcification that uses EDTA

Answer 13

Use of chelating agent

Question 14

Method of decalcification that is not suited for urgent biopsies

Answer 14

Ion Exchange Resin

Question 15

Duration of decalcification thru ion exchange resin

Answer 15

1-14 days

Question 16

Most reliable and accurate method of testing used to measure the extent of decalcification
Can detect the smallest calcium

Answer 16

Xray/Radiologic

Question 17

Done by bending the tissue, probing or pricking the tissue with needle

Answer 17

Mechanical/Physical

Question 18

Method of testing for the completeness of decalcification that uses calcium carbonate

Answer 18

Bubble Test

Question 19

If after adding CaCO3 > present of tiny bubbles > specimen is not yet calcified > what is the next step?

Answer 19

Extend decalcificaiton

Question 20

Uses 5mL or 0.5mL decalcifying agent (acidic in nature) + strong ammonia > alkaline

Answer 20

Chemical method

Question 21

In chemical method, if the result is turbid, the decalcification is not yet _

Answer 21

Complete

Question 22

• Most potent anticoagulant but weak decalcifying agent
• Binds with calcium to form weakly dissociated complexes
• An excellent bone decalcifier for EM and Enzyme histochemistry

Answer 22

EDTA

Question 23

Disadvantage of EDTA

Answer 23

It can inactivate alkaline phosphatase

Question 24

Remmedy for inactivation of alkaline phosphatase by EDTA

Answer 24

Magnesium chloride

Question 25

• Decalcification method that involves attraction of positively charged calcium ions with negatively charged electrode
• Most rapid decalcification method
• Application of electric current in a specimen submerged in acid

Answer 25

Electrolytic Method

Question 26

Decalcifying acid used for surface decalcification of blocks

Answer 26

Von Ebner’s

Question 27

Von Ebner’s composition

Answer 27

HCl + Saline (NSS)

Question 28

Both a decalcifying agent and a tissue softener

Answer 28

Pereyni’s Fluid

Question 29

Most commonly used decalcifying agent especially recommended for urgent biopsies, for needle and small biopsies

Answer 29

5-10% Nitric Acid

Question 30

Most rapid nitric containing decalcifying agent

Answer 30

Phloroglucin Nitric Acid