Eastwood and Cole Congo Red
for Amyloid

Solutions

Mayer's hemalum.

Buffer pH 10
Glycine, 0.1M	30	mL
Sodium chloride, 0.1M	30	mL
Sodium hydroxide, 0.1M	40	mL

Congo red
Congo red	0.5	g
Buffer pH 10	50	mL
Ethanol, absolute	50	mL
Combine the ethanol and buffer.
Dissolve the congo red.

Tissue sample
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable.

Method

1. Bring sections to water via xylene and ethanol.
2. Stain nuclei with hemalum and blue.
3. Place in congo red solution for 10 - 20 minutes.
4. Rinse off the staining solution with 70% ethanol until clear.
5. Dehydrate with ethanol.
6. Clear with xylene and mount with a resinous medium.

Expected results

• Amyloid  –  Orange to red
• Eosinophils and elastic  –  Orange to red
• Nuclei  –  Blue

Notes

1. Amyloid displays apple green birefringence when viewed with crossed polarisers, one above and one below the section.

 

Reference
Bancroft, J.D. and Stevens A. (1982)
Theory and practice of histological techniques Ed. 2
Churchill Livingstone, Edinburgh & London, UK.