Advancements of the sFIDA method for oligomer-based diagnostics of neurodegenerative diseases.

Early diagnosis of Alzheimer's disease (AD) is of great importance for the development of therapeutics and their application in the clinical environment. Amyloid β (Aβ) oligomers are crucial for the onset and progression of AD and represent a popular drug target, being presumably the most direct biomarker. Efforts to measure Aβ oligomers in body fluids are hampered by the low analyte concentration and presence of Aβ monomers. The surface-based fluorescence intensity distribution analysis (sFIDA) features both highly specific and sensitive oligomer quantitation as well as total insensitivity towards monomers. In this Review, we highlight structural features of oligomeric and fibrillar Aβ. Recent advancements in sFIDA assay development have been the successful automation, adaption for additional biomarkers such as α-synuclein oligomers, and significant improvement of essential assay parameters.