Barthelemy on mass spec (IMAGE) Washington University School of Medicine Caption Nicolas Barthelemy, PhD, an instructor in neurology at Washington University School of Medicine in St. Louis, loads a sample into a mass spectrometer. Barthelemy and colleagues used mass spectrometry to discover that a form of the Alzheimer's protein tau is found at high levels in the blood of people in the earliest stages of Alzheimer's disease. The discovery could pave the way toward a blood-based test to diagnose the neurodegenerative disease before symptoms appear. Credit Matt Miller Usage Restrictions This image is to be used in accordance with the mission, policies and guidelines of Washington University in St. Louis. Visit https://wustl.edu/about/compliance-policies/media-policies/photo-use/ for more information. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.