MAPT and Alzheimer disease: By using tau151-391, we introduce the development of two simple assays with routine biochemical techniques, an in vitro tau capture assay and in cultured cells a seeded-tau aggregation assay, for the assessment of tau seeding activity and validated the assays using the extracts from middle frontal gyrus (MFG), middle temporal gyrus (MTG), and basal forebrain (BFB) of AD and control brains.