The quest for the causative agent in Alzheimer’s Disease has recently focused on the precursors of amyloid plaques. These precursors are part of a bewildering array of processed APP variants, Tau isoforms and secretase components that play a role in neuronal cytotoxicity and subsequent brain dysfunction. A trio of highly-sensitive antibodies to beta-amyloid are available. The affinity-purified rabbit polyclonal antibodies recognize both human and mouse Aβ and have been shown to be effective in Western, immunohistochemistry and ELISA applications. The antibodies detect <1; ng/ml protein by Western, and <1; pg/ml by ELISA.