ALKALINE CONGO RED TECHNIQUE

 

SECTIONS

4µm paraffin wax sections

SOLUTIONS

1. STOCK ALCOHOLIC SALT SOLUTION

--Saturated sodium chloride in 80% alcohol

2. WORKING SOLUTION

--Stock solution (1) 50cm3
--1% Sodium hydroxide 0.5cm3

--Mix, filter and use within 15 minutes

3. STOCK CONGO RED SOLUTION

Saturated Congo Red in 80% alcohol saturated with sodium chloride

4. WORKING SOLUTION

--Stock solution (3) 50cm3
--1% Sodium hydroxide 0.5cm3

 

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METHOD

1. Sections to water

2. Stain nuclei lightly with Gills Haematoxylin

3. Wash in water and 'blue' in 1% lithium carbonate

4. Treat with working solution (1) for 20 minutes

5. Drain off and treat with Congo Red working solution (4) for 20 minutes

6. Rinse in alcohol. Dehydrate, clear . Mount sections in DPX

 

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RESULTS

--Amyloid, eosinophils, elastic - Dull red

--Nuclei - Blue

--Background - Clear