Highman's Congo Red
for Amyloid
Materials
Tissue Sample
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable. Other fixatives are likely to be satisfactory.
Protocol
- Bring sections to water via xylene and ethanol.
- Place into congo red solution for 5 minutes or longer.
- Differentiate in alkaline ethanol (about 5-30 seconds).
- Wash well with tap water.
- Stain nuclei with hematoxylin and blue.
- Dehydrate with ethanol.
- Clear with xylene and mount with a resinous medium.
Expected Results
- Amyloid – orange red
- Nuclei – blue
- Background – colorless
Notes
- Amyloid displays apple green birefringence when viewed with crossed polarisers, one above and one below the section.
- Sirius red F3B may also be used in this method.
Safety Note
Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.
References
- Highman, B., (1946),
Improved methods for demonstrating amyloid in paraffin sections,
Archives of Pathology, v 41, page 559 - Bancroft, J. D. and Stevens, A.
Theory and practice of histological techniques,
Churchill Livingstone, London, England