Fig. 3.

Representative images of [¹⁸F]-Flortaucipir (left), [¹⁸F]-MK-6240 (center), and [¹⁸F]-PI-2620 phosphor screen autoradiography experiments run in parallel with and without adding methanol/ethanol to the protocol washing steps. The parallel experiments yielded identical results: strong binding of the three tracers was observed in cortical regions containing tangles (occipital cortex) from AD brains. No signal was detected in regions containing tau aggregates in PSP (basal ganglia), CTE brains (parietal cortex) or in control brains (frontal cortex) without pathology. The signal was blocked by adding the appropriate unlabeled tracer in each case. Abbreviations AD, Alzheimer disease; CTE, chronic traumatic encephalopathy; PSP, progressive supranuclear palsy. Scale bar = 1 cm