One of the hallmarks of Alzheimer's disease is the presence of amyloid plaques in the brain. One of the main constituents of the plaques is the peptide amyloid beta. Over the last decade, research from animals and humans have pointed to plaques as a leading cause for the progression of Alzheimer's disease and research in humans have shown that amyloid plaques are most likely present in the brain before any clinical signs of Alzheimer's disease (such as memory loss) are present. It has also become clear over the past decade that in order to develop therapeutics that can prevent or slow down the progression of Alzheimer's disease it is important to diagnose as early as possible. Ideally such a diagnostic test would be easy to administer and have high predictive value. In this proposal, C2N Diagnostics will seek to develop a blood based diagnostic test which will assess the level of plaques in the brain and thus allow pre-clinical diagnosis of Alzheimer's disease. This will greatly aid in the clinical trials for amyloid plaque modifying therapeutics and once such drugs get approved this test could be an important screening test to select people that should be on such drugs.