Aβ and Tau seeds have the potential to serve as biomarkers for AD. The AD-seeds-detector could detect small quantities of Aβ and Tau seeds by taking advantage of their ability to nucleate and enhance aggregation, enabling a very high amplification of the signal. This study examines the effectiveness of using the AD-seeds-detector as a novel technique for discriminating AD from cognitively normal control and non-AD dementia by detecting small Aβ and Tau seeds in plasma.~This will be an observational study aiming at using the AD-seeds-detector to detect minute amounts of Aβ and Tau seeds in plasma as novel biomarkers with high sensitivity and specificity for the accurate diagnosis of AD. To achieve this goal, the investigators will conduct two studies using the AD-seeds-detector to detect the Aβ and Tau seeds in the plasma samples.~Study one:~A single-center cohort that consists of well-characterized AD patients (n=150), cognitively normal controls (n=100) and non-AD dementia patients (n=50).~Study two:~A multi-center cohort with well-characterized AD patients (n=400), cognitively normal controls (n=400) and non-AD dementia patients (n=400).
The study will investigate the biomarkers of Aβ and Tau seeds in plasma detected by Alzheimer's disease (AD) related seeds quantitative detector (AD-seeds-detector), and their sensitivity and specificity in diagnosing AD, compared with those from age-matched cognitively normal controls, and those with other types of dementia.~To perform a high throughput analysis of the amount of Aβ and Tau seeds, the investigators have developed an AD-seeds-detector, in which a fluorescence microplate reader was combined with an oscillating mixer or water-bath-type ultrasonicator.