The solid-phase synthesis and purification of the 1-40 sequence of the human beta-amyloid were optimized, resulting in a preparation of a product with a high yield and homogeneity more than 95%. The synthetic peptide is capable of forming oligomers. This fact was confirmed by electrophoresis in the polyacrylamide gel with a subsequent immunoblotting and fluorescence spectrophotometry using the thioflavin T dye. An available method for a production of the highly specific anti-beta-amyloid antibodies with a high titer was developed. These antibodies recognized both monomeric and oligomeric forms of the 1-40 peptide of beta-amyloid under the immunoblotting conditions.