Intrinsic fluorescence–based label-free detection of bovine amyloid A amyloidosis

Amyloidosis is diagnosed by the histologic detection of amyloid deposits; however, this method has limitations such as a prolonged diagnosis time and the need for histologic proficiency. We aimed to develop a rapid and simple method for diagnosing amyloidosis by targeting amyloid-specific endogenous fluorescence, which has not been reported previously, to our knowledge. Fluorescence fingerprint analysis of amyloid extracts and tissue homogenates derived from amyloid A (AA) amyloidosis-affected cattle exhibited a specific intrinsic fluorescence pattern. Furthermore, principal component analysis using analytical data revealed that AA could be identified by peaks near λex 350 nm and λem 430 nm. Fluorescence spectrometry analysis using tissue homogenates, which does not require special histochemical staining, enables the rapid detection of bovine AA.