Many pathologists use Congo red to make a diagnosis of amyloid and state the common opinion that in polarized light, Congo red-stained amyloid shows apple-green birefringence, sometimes called ...

Congo red staining with exhibition of an apple-green birefringence is diagnostic of amyloid. Immunohistochemistry can detect amyloid deposits but has limitations, and newer molecular techniques ...

This is called apple-green birefringence. Once the amyloidosis is confirmed by biopsy, the type of amyloidosis is determined. The different types of amyloidosis are classified according to the ...

Histologic examination with Congo red staining reveals eosinophilic infiltrate in the papillary dermis, with apple green birefringence.