ß-Amyloid (1-40) is a primary protein in plaques found in the brains of patients with Alzheimer's disease. It is the major component of senile plaque amyloids, are physiological peptides present in the brain, cerebrospinal fluid (CSF) and plasma.This peptide is biotinylated at its N-terminu. Biotin is widely used throughout the biotechnology industry to conjugate proteins for biochemical assays. Biotin can be used for qualitative and quantitative detection, labelling or immobilisation.