Fluorescence microscopy images of the brain extract samples labeled with CyDPA2 (10 μM, λexi/ λemi = 783/800 nm). In (D), (E), and (F), CyDPA2 was pretreated with 100 μM of sodium pyrophosphate (ppi). Scale bars = 50 μm. (A) AD, (B) P301L, (C) nTau protein, (D) AD + ppi, (E) P301L + ppi, and (F) nTau protein + ppi.