Zunaira saleh3 months ago

Diagrammatic representation of the ultrastructure of amyloid.a

A, Electron microscopy shows major part consisting of amyloid fibrils (95%) randomly oriented, while the minor part is essentially P-component (5%) B, Each fibril is further composed of double helix of two pleated sheets in the form of twin filaments separated by a clear space. P-component has a pentagonal or doughnut profile. C, X-ray crystallography and infra-red spectroscopy shows fibrils having cross-β-pleated sheet configuration which produces periodicity that gives the characteristic staining properties of amyloid with Congo red and birefringence under polarising microscopy.