<p>The aim of this study was to assess the use of Synchrotron Radiation Fourier Transform InfraRed micro spectroscopy (SR micro-FTIR) in the diagnosing and subtyping of different misfolded proteins in various tissues and organs. To this end, specimens from various organ sites were investigated. Multivariate data analysis was applied to correlate the spectral datasets with histological and immunohistochemical findings and clinical data. The results of the study reveal significant segregation of tissues affected by amyloidosis and controls, but the observed amount of amyloid β-sheet did not correlate with the disease state. Amyloid light-chain type specimens contained more βsheet structures than non-Amyloid a types, and Tran’s thyretrin type showed very little. The Insulin type behaved differently</p>