We report the development of a high-level bacterial expression system for the Alzheimer’s disease-associated amyloid b-peptide (Ab), together with a scaleable and inexpensive purification procedure. Ab(1–40) and Ab(1–42) coding sequences together with added ATG codons were cloned directly into a Pet vector to facilitate production of Met-Ab(1–40) and Met-Ab(1– 42), referred to as Ab(L1–40) and Ab(L1–42), respectively.