Fig. 8

β-synuclein competition ELISA assays. a The two site inhibition curves show high and low binding components in pooled plasma samples from Parkinson’s Disease (PD-blue, squares), Multiple System Atrophy (MSA-green, triangles) patients and normal control (NC-black, circles) subjects. 10 μg/mL β-synuclein coating, plasma dilution 1:400; b and c: Binding of anti-β-synuclein NAbs in individual plasma samples to immobilized β-synuclein monomer (10 μg/mL) in competitive ELISA assay in the presence of b 100 nM or c 10 nM free β-synuclein. Non-specific binding is defined as the binding to the plate in the presence of 1000 nM free β-synuclein monomer. Maximal binding is defined as the binding observed in the absence of added free β-synuclein monomer. Plasma samples were tested at 1:400 dilution. Horizontal bars represent the mean values +/− SEM. Significance was tested using Man–Whitney’s U test (P < 0.05)