Which one of the following stain is specific for amyloid

Ref Robbins 9/e p257; Harrison 17/e p2145 Amyloid is not a structurally homogeneous protein, although it always has the same morphologic appear- ance. In fact, more than 20 (at last count, 23) different pro- teins can aggregate to form fibrils with the appearance of amyloid. Regardless of their derivation, all amyloid deposits are composed of nonbranching fibrils, 7.5 to 10 nm in diam- eter, each formed of b-sheet polypeptide chains that are wound together (Fig. 4-31). The dye Congo red binds to these fibrils and produces a red-green dichroism (birefrin- gence), which is commonly used to identify amyloid deposits in tissues.