Fig. 2

Extracellular Tau aggregates accumulate more than monomers in human iPSC-derived neurons. A Schematic representation of the uptake and accumulation assay. First, cells were treated with fluorescently ATTO488-labeled Tau. After a defined incubation time, the culture medium was changed to a quenching medium to eliminate the extracellular but not the intracellular fluorescence. Finally, a fluorescence plate reader quantified the well surface fluorescence in a 96-well–plate with a transparent bottom. UTC: untreated control. B Live images of cells (DIV 15) treated with 100 nM ATTO488-labeled Tau Monomers (Mono) or aggregates (Agg) for 24 h in the presence of the quencher. Scale bar: 100 μm. C Time-dependent uptake of 100 nM ATTO488-labeled Tau Monomers and aggregates, quantified on a fluorescence plate-reader in the presence of the quencher. D Concentration-dependent uptake of ATTO488-labeled Tau Monomers and aggregates (monomer equivalent) after 24 h on a fluorescence plate-reader in the presence of the quencher. Fluorescence values are normalized by dividing by the background. Error bars represent SD; n = 3 per experimental condition. One-way ANOVA followed by post-hoc test; ns: not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 vs. Mono