Quiz on Amyloid Staining and Appearance

What color does amyloid show under polarized microscopy after staining with Congo red?

• Pink

• Red

• Apple-green

• Mahogany brown

What is the appearance of amyloid under light microscopy?

• Yellow color under UV light

• Amorphous, eosinophilic, hyaline, extracellular substance

• Nonbranching fibrils

• Cross-β-pleated sheet conformation

What is the characteristic appearance of amyloid using Congo red stain under ordinary light?

• Apple-green birefringence

• Yellow color

• Pink or red color

• Mahogany brown

What does electron microscopy reveal about amyloid?

• Apple-green birefringence

• Nonbranching fibrils with a diameter of approximately 7.5 to 10 nm

• Yellow color under UV light

• Pink or red color

What is the appearance of amyloid on iodine staining?

• Rose-pink

• Apple-green

• Mahogany brown

• Yellow

Which method shows amyloid as having a yellow color under UV light?

• Congo red stain

• Fluorescent stains (thioflavin T and S)

• Electron microscopy

• X-ray crystallography

What is the characteristic conformation of amyloid as revealed by X-ray crystallography and infrared spectroscopy?

• Amorphous eosinophilic substance

• Nonbranching fibrils

• Cross-β-pleated sheet conformation

• Yellow color

What color does amyloid appear when stained with crystal violet?

• Mahogany brown

• Rose-pink

• Apple-green

• Yellow

What is the appearance of amyloid under Congo red stain on polarizing microscopy?

• Pink or red color

• Apple-green birefringence

• Yellow color

• Mahogany brown

What is the appearance of amyloid under fluorescent stains (thioflavin T and S)?

• Apple-green birefringence

• Yellow color under UV light

• Pink or red color

• Mahogany brown