Congo red principle Flashcards
What unique conformation do amyloid proteins have?
β-pleated sheet conformation
How do Congo Red molecules bind to amyloid proteins?
Through hydrophobic and hydrogen bonding interactions
What type of arrangement do Congo Red molecules have when interacting with amyloid fibrils?
Stacking arrangement
What color do Congo red-stained amyloid deposits appear under normal light?
Red
What effect does the alignment of Congo Red molecules have under polarized light?
Apple-green birefringence
What is the role of potassium hydroxide in 80% alcohol in staining?
Differentiates stain by removing nonspecific dye binding
Why is potassium hydroxide diluted in alcohol during the differentiation process?
To slow down the differentiation so it does not occur too quickly
WHat counterstain is used?
Mayers Haematoxylin
Stain colour results
Amyloid red
Nuclei blue
Why is congo red diluted in alcohol?
Break internal hydrogen bonding between polysaccharides, creating more potential binding sites for the dye.
