DECALCIFICATION OF CALCIFIED TISSUE Flashcards
When is decalcification process carried out
it is carried out between fixation and dehydration
what is decalcification
is the removal of calcium ions from a bone or calcified tissue through a histologic process that makes them flexible and easier to cut
what are the effects of not doing decalcification
- It can result to poor cutting of tissues
- Damages to knife used in cutting in latter process
how is penetration of decalcifying agent achieved
the bones, tissue are first cut into small pieces with saw and razor blade to allow penetration
differentiate between dystrophic calcification
Dystrophic calcification means the deposition occurs locally in dying tissues
while
Metastatic calcification means the deposition of calcium salts in otherwise normal tissues
what is pathologic calification
is the abnormal tissue deposition of calcium salts
mention the common decalcifying agents
- Dissolution of calcium by a diluted mineral ACID
- Use of Chelating agents e.g EDTA (PH 7)
- By using diluted mineral and along with ion exchange resin to keep the decalcifying fluid free of calcium
- Electrophoresis. Electrolytic removal of calcium ions from tissue by the use of electric current
- Microwave oven decalcification
What is the function of chelating agents
Chelates calcium to form a soluble salt (VERSENE(solid) and SEQUESTRENE (liquid))
Mention the strong acids used in histology
- Nitric acid (12-24 Hrs)
- Perenyi’s fluid (2-7 days)
- Phloroglucin-Nitric acid (12-24 hours)
- Hydrochloric Acid
what is the description of perenyi’s fluid
both tissue softener and decalcifying agent. Staining is enhanced and good for tissues with small calcium deposits
how is nitric acid prepared
concentated nitric acid 10 mL with distilled water 100mL
What are the advantages of nitric acid
rapid in action
produces minimum shrinkage
produces good nuclear staining
recommended for urgent biopsy, needle and small biopsy
