Intracellular (A) naked or (B) lipofectamine-mediated tau seeding in nontargeting control (Non-Target, purple), DnaJC7 KO (ΔC7, orange), and DnaJB6 KO (ΔB6, green) tau biosensor cells. Cells were seeded with sonicated recombinant tau fibrils (rTau); brain lysates from patients with Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), or corticobasal degeneration (CBD); and cell lysates of DS1, DS9, or DS10 cells. 100nM or 10nM of recombinant tau were added for naked and Lipofectamine seeding, respectively. 25μL or 5μL of patient brain or lysate or 20μg or 5μg cell lysate were added for naked and Lipofectamine seeding, respectively. NT denotes no treatment with seeds. Error bars represent SEM of three technical replicates. *=p < 0.05, **=p < 0.01, ***=p < 0.001, ****=p < 0.0001.