Other Methods

Front 1

Decalcification

Back 1

• Bone and Teeth contain calcium and phosphate salts which prevent sectioning

• Decalcification is needed to soften these mineralised tissues before processing
  

Front 2

Agents (2)

Back 2

• Acids: removal of hydroxyapatite .

- Formic Acid 2-10days renew 24h

- Nitric Acid up to 2 days

- Hydrochloric Acid

• Chelating agents

- eg. Ethylenedisminetetraacetic Acid (EDTA) 6-8 weeks

Front 3

Factors effect decalcification (6)

Back 3

• Temperature
• Agitation
• Volume of fluid
• Frequency of change
• Concentration of decalcifying fluid
• Ion exchange resins

Front 4

Determination of End Point (3)

Back 4

• X-rays
  
• Chemical testing
• Manual testing

Front 5

Properties of a Good Agent (4)

Back 5

• Complete removal of Calcium
• No damage to tissue
• No impairment of subsequent staining techniques
• Reasonable speed

Front 6

Surface Decalcification

Back 6

• Used when unsuspected calcium deposts are found when sectioning
  
• Block placed face-down in an solution for 15-60 minutes

- 1% HCl

- 1% Formic acid

- Von Ebne's solution; Contains HCl and NaCl may be used on Ebner's solution

Front 7

Undecalcified Bone

Back 7

• Used in demonstrating bone mineral and its relationship to the unmineralised components of bone

• Used for diagnosis of Osteomalcia and Osteoporosis

• Acrylic resins or plastics are used as paraffin wax too soft to provide strong support