MAPT and Alzheimer disease: Cryoelectron microscopy analysis showed no major effects of the Sarkosyl treatment on the structure of Aß and tau fibrils [39], although Sarkosyl-untreated Aß, i.e., the ultracentrifugation supernatant of Tris-buffered saline extracts of Alzheimer’s disease brain, showed shorter fibrils that clumped less, suggesting that Sarkosyl may enhance fibril association [40].