Combined use of micro-preparative gel electrophoresis and reversed-phase high-performance liquid chromatography for purification of amyloid β peptides deposited in brains of Alzheimer’s disease patients

A new micro-technique is developed for purification of amyloid β peptides (Aβ) extracted from brain tissues of patients with Alzheimer’s disease (AD). It includes SDS–polyacrylamide gel electrophoresis of the extracted brain tissue material, electroblotting onto supporting membranes, and reversed-phase HPLC of the proteins eluted from membranes. By this technique, the extracted Aβ are first separated electrophoretically from the higher and lower molecular mass tissue components, and then purified by reversed-phase HPLC from the contaminants having similar molecular masses, but different retention times on the column. In contrast to the common large-scale isolation procedures employing density gradient centrifugation, enzymatic digestions and size-exclusion chromatography, the developed micro-technique might be applied for biochemical analysis of Aβ contained in small AD brain tissue specimens.