MAPT and Alzheimer disease: While our FTA apparently was able to detect captured tau aggregates, to further determine the morphology of the amplified skin tau aggregates, we performed transmission electron microscopy (TEM) of the RT-QuIC end-products of skin misfolded tau from 3 cases each of AD, PSP, CBD, PiD and NCs with either 4RCF or 3RCF as the substrate (Fig. 7).