Clusters of abnormally folded α-synuclein proteins, called seeds, trigger the formation of larger aggregates, leading to neurodegenerative disorders known as synucleinopathies. Researchers from Japan have developed a novel assay that can detect α-synuclein seeds in the blood. This new assay is highly sensitive, simple, quick, and can differentiate between synucleinopathies based on structural differences of the amplified seeds. This research was supported by the National Research Program for Neurological Disorders and Mental Health of the Japan Agency for Medical Research and Development (AMED).