Congo Red Fluorescence

for Amyloid

steps

materials

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Expected Results

fig1-congo-red-staining-amyloid-lipofuscin-autopsy-senile-cardiac-amyloidosis-600x400

Figure 1. Congo Red Staining Showing Amyloid and Lipofuscin in an Autopsy Specimen of Senile Cardiac Amyloidosis

Congo red staining of an autopsy specimen of senile cardiac amyloidosis, showing amyloid (extracellular washed-out red material) and abundant lipofuscin (yellow granular material). Cardiac amyloidosis very high mag by Nephron / Michael Bonert, Pathology & Molecular Medicine, McMaster University is licensed under CC BY-SA 3.0.

Amyloid – Orange to red fluorescence

Materials

Congo red

Material	Amount
Congo red	0.1	g
Ethanol, 50%	100	mL

Differentiator

Material	Amount
Potassium hydroxide	0.2	g
Ethanol, 80%	100	mL

Tissue Sample

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

Protocol

Bring sections to water via xylene and ethanol.
Place into congo red for 1 minute.
Wash with tap water.
Place into differentiator until the section appears to be unstained.
Wash with water.
Dehydrate with absolute ethanol.
Clear with xylene.
Mount with a fluorescence free resinous medium.

Notes

This method is very similar to Highmans procedure.

Safety Note

Prior to handling any chemical, consult the Safety Data Sheet (SDS) for proper handling and safety precautions.

References

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

Congo Red Fluorescence for Amyloid