Tau aggregation and neurofibrillary tangle formation represent central pathological hallmarks of Alzheimer’s disease (AD). Although tau immunohistochemistry is widely used to characterize neurodegeneration, conventional approaches often rely on single antibodies and semi-quantitative pathological scoring, limiting the ability to distinguish between different biochemical states of Tau. The NDT Antibodies enable the distinction between different biochemical states of tau including native, proteolytically cleaved, and aggregated tau.