Amyloid beta (Aβ) is a peptide consisting of 36-43 amino acids that plays a pivotal role in the pathogenesis of Alzheimer’s disease (AD). Specifically, the ratio of amyloid beta 42 to amyloid beta 40 (Aβ42/40) has garnered significant attention in the realm of AD research and diagnostics. Amyloid beta 42 (Aβ42) and amyloid beta 40 (Aβ40) are two major isoforms of Aβ, differing in their lengths and aggregation properties. Aβ42 is more prone to aggregate and form toxic oligomers and fibrils compared to Aβ40. Consequently, the Aβ42/40 ratio serves as a critical indicator of the pathological processes underlying AD. Download our fact sheet to learn more.