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Learn how to use Congo red stain to identify amyloid deposits in tissue sections, a direct diazo dye that forms complexes with misfolded proteins. See the definition, pathophysiology, clinical features, interpretation and microscopic images of amyloidosis.
Jan 1, 2019 · Staining with Congo Red (CR) is a qualitative method used for the identification of amyloids in vitro and in tissue sections. However, the drawbacks and artefacts obtained when using this dye can be found both in vitro and in vivo.
In histology and microscopy, Congo red is used for staining in amyloidosis, and for the cell walls of plants and fungi, and for the outer membrane of Gram-negative bacteria. Apple-green birefringence of Congo red stained preparations under polarized light is indicative of the presence of amyloid fibrils.
Jan 9, 2022 · Learn how to use Congo red stain to identify amyloids in tissue sections. Find out the principle, methodology, quality aspects, and applications of this staining technique.
Congo red is a dye that changes color in acidic environments and is used to detect intestinal metaplasia and gastric cancers. It is also a histological stain for amyloid, a protein disorder that shows green birefringence under polarized light.
Jul 16, 2023 · The biochemical properties that lead to positive staining in Congo Red are poorly understood. It is thought that a properly made, appropriately linear molecule of Congo Red has affinity for the beta pleated sheets that are the common make up of amyloid.
Oct 9, 2019 · Selective congo red staining (congophilia) by amyloid is attributed to formation of non-ionic hydrogen bond between amyloid and dye imparting it deep pink to red color (Fig. 1 b). It is enhanced by alkaline PH and depends on thickness of section. 6–10 µ thick sections are required for optimal staining.
