Amyloid Stain (Congo Red)

Reagent Preparation

Sodium Hydroxide solution is supplied ready to use. Alkaline Sodium Chloride solution is prepared by adding 0.4 mL Sodium Hydroxide solution to 40 mL Sodium Chloride solution. Mix just before use. Use once and discard. Alkaline Congo Red solution is prepared by adding 0.4 mL Sodium Hydroxide solution to 40 mL Congo Red solution. Filter and use within 15 minutes.

Procedure

  1. Deparaffinize tissue sections and hydrate to deionized water.
  2. Stain in Gill’s No. 2 Hematoxylin solution for 3 minutes.
  3. Wash in tap water for 5 minutes.
  4. Place in Alkaline Sodium Chloride solution for 20 minutes.
  5. Remove slides and place in Alkaline Congo Red solution for 20 minutes.
  6. Rinse in three changes of absolute alcohol.
  7. Clear slides in xylene and coverslip.

Results

Amyloid – Pinkish red to red
Nuclei – Blue
Background – Pink
*When examined under polarizing light, amyloid shows green birefingence.


Amyloid Stain (Congo Red)

Reagents

     
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