Researchers assessed DNA methylation at 800,000 sites in the genome in blood samples collected from 900 people. The study includes extensive clinical information on participants, who all provided spinal fluid samples, which have been used for diagnosis and monitoring of Alzheimer's disease, because it is in direct contact with the brain. However, collecting the fluid is an invasive procedure, so the team investigated whether they could instead use blood samples, through analyzing blood epigenetic signatures that are associated with Alzheimer's disease biomarkers, as this would be cheaper and easier to collect in practice.
