Alzheimer’s disease affects millions worldwide—but confirming a diagnosis is far from simple. Doctors currently rely on costly brain scans or invasive spinal fluid tests to identify the condition—methods that can be stressful, time-consuming and out of reach for many patients.

Alzheimer’s disease biomarkers measured from finger-prick dried blood samples closely match standard plasma tests and predict CSF pathology with good accuracy, a large-scale study shows.