Congo Red has been used in microscopy for staining elastic fibers and bacteria. Amyloid protein, an abnormal protein aggregate associated with various pathologies, is commonly detected in tissue with Congo Red. Detection of amyloid is relevant for a whole host of diseases, including Alzheimer's disease, Creutzfeld-Jakob's disease and Bovine Spongiform Encephalopathy. The birefringence of Congo Red-stained amyloid, appearing green under polarized light, improves detection relative to simple visible examination of the colored deposits. Additionally, upon binding to amyloid, Congo Red displays bright fluorescence emission at 614 nm with excitation at 497 nm.    Biotium offers high purity grade of Congo Red with HPLC purity greater than 97%.    Red solid soluble in water, DMSO, EtOH  Stored desiccated at 4°C  C32H22N6Na2O6S2  MWt: 696.66  [573-58-0]