Development of Homogeneous 384-Well High-Throughput Screening Assays for A 1-40 and A 1-42 Using AlphaScreenTM Technology

Amyloid beta (A beta) peptides are the major constituent of amyloid plaques, one of the hallmark pathologies of Alzheimer's disease. Accurate and precise quantitation of these peptides in biological fluids is a critical component of Alzheimer's disease research. The current most established assay for analysis of A beta peptides in preclinical research is enzyme-linked immunosorbent assay (ELISA), which, although sensitive and of proven utility, is a multistep, labor-intensive assay that is difficult to automate completely. To overcome these limitations, the authors have developed and optimized simple, sensitive, homogeneous 384-well assays for A beta 1-42 and A beta 1-40 using AlphaScreen (TM) technology. The assays are capable of detecting A beta peptides at concentrations < 2 pg/mL and, using a final assay volume of 20 mu L, routinely generate Z ' values > 0.85. The AlphaScreen (TM) format has the following key advantages: substantially less hands-on time to run, easier to automate, higher throughput, and less expensive to run than the traditional ELISA. The results presented here show that AlphaScreen (TM) technology permits robust, efficient, and cost-effective quantitation of A beta peptides.