Polymorphism of Amyloid Fibrils Monitored by Polarization Resolved Microscopy

Amyloid fibrils are proteins misfolding structures that involve a beta-sheet structure and are associated with the pathologies of various neurodegenerative diseases. We show that Thioflavine-T and Congo Red, two major dyes used to image fibrils by fluorescence assays, can provide deep structural information when probed by means of polarization resolved fluorescence microscopy [1]. This technique allows indeed to retrieve simultaneously both mean orientation and orientation dispersion of the dye, used here as a reporter of the fibril structure [2].