A digital enzyme-linked immunosorbent assay for ultrasensitive measurement of amyloid-β 1–42 peptide in human plasma with utility for studies of Alzheimer’s disease therapeutics

Background Amyloid-β 1–42 peptide (Aβ1–42) is associated with plaque formation in the brain of patients with Alzheimer’s disease (AD). Pharmacodynamic studies of AD therapeutics that lower the concentrations of Aβ1–42 in peripheral blood require highly sensitive assays for its measurement. A digital enzyme-linked immunosorbent assay (ELISA) using single molecule array (Simoa) technology has been developed that provides improved sensitivity compared with conventional ELISA methods using the same antibody reagents.