Exosome Photo (IMAGE) Brain Chemistry Labs Caption Neurally-derived extracellular vesicles extracted from a standard blood sample contain microRNA sequences used to diagnose ALS. Credit Photograph by Paul Cox. Usage Restrictions No restriction License Original 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.