ACID DECALCIFYING AGENTS part 2

TRICHLOROACETIC ACID

FORMULA:

• Trichloroacetic acid 5 gm

• Formal saline 10% 95 ml

4- 8 days

TRICHLOROACETIC ACID DECALCIFICATION TIME:

Trichloroacetic acid

• It permits good nuclear staining.

• It does not require washing out; the excess acid may be removed by several changes of 90% alcohol, thus improving tissue dehydration.

Trichloroacetic acid

It is a weak decalcifying agent, not used for dense tissues, and is suitable only for small spicules of bone.

Trichloroacetic acid

It is very slow-acting; hence, is not recommended for urgent examinations

SULFUROUS ACID

is a very weak decalcifying solution suitable only for minute pieces of bone

CHROMIC ACID (FLEMMING'S FLUID)

FORMULA:

• Chromic acid % 15 ml.

• Osmium tetroxide 4 ml.

• 2% Glacial acetic acid 1 ml

Chromic acid

Chromic acid

• It may be used both as a fixative and decalcifying agent.

• It may be used for decalcifying minute bone spicules

Chromic acid

• Nuclear staining with hematoxylin is inhibited.

• It tends to undergo reduction and forms precipitates at the bottom of the container thus requiring frequent changes of solution

Chromic acid

• Insoluble pigments are formed when decalcified tissue is dehydrated with alcohol; hence, tissues must be washed out prior to dehydration.

• Degree of decalcification cannot be measured by the routine chemical test

6 days

CITRIC ACID-CITRATE BUFFER SOLUTION DECALCIFICATION TIME:

CITRIC ACID-CITRATE BUFFER SOLUTION

FORMULA:

• Citric acid (monohydrate) aqueous solution 7% 5.0 ml.

• Ammonium citrate (anhydrous) aqueous solution 7.4% 95.0 ml.

• Zinc sulfate aqueous solution. 1% 0.2 ml. Chloroform (as preservative) - a few drops

CITRIC ACID-CITRATE BUFFER SOLUTION

• It permits excellent nuclear and cytoplasmic staining.

• It does not produce cell or tissue distortion

CITRIC ACID-CITRATE BUFFER SOLUTION

Its action is too slow for routine purposes