Mouse anti tau1

For analysis, cells were fixed for 30 min in 4% paraformaldehyde in phosphate-buffered saline (PBS), permeablized in 0.25% Triton X-100 for 15 min, and then blocked with 4% BSA in PBS for 2 hours at room temperature or overnight at 4°C. Cultures were incubated with primary antibodies in 4% BSA for 2 hours at room temperature, rinsed with PBS, incubated with secondary antibodies for 1 hour, and were again rinsed with PBS. Cell nucleus were also stained with 4′,6-diamidino-2-phenylindole (DAPI) before imaging. The primary antibodies included mouse anti-Tau1 (Millipore), rabbit anti-MAP2 (Millipore).

For morphological analysis, the cells were fixed in 4% paraformaldehyde (PFA) for 10 minutes at room temperature followed by three rinses in phosphate buffered saline (PBS). The cells were then permeabilized in 0.25% Triton X‐100 for 10 minutes at RT, followed by three washes in PBS, and incubation in a blocking solution of 3% bovine serum albumin (BSA), 3% normal goat serum (NGS), 0.1% Tween 20 (T20), for 1 hour at RT. Soon after, the cells were incubated with primary antibodies for 1 hour at RT or overnight at 4°C. Thereafter, the cells were again washed three times with PBS, followed by incubation with fluorescently conjugated secondary antibodies (diluted in BSA/NGS/T20). To stain the nuclei, the cells were counterstained with DAPI (4′,6‐diamidino‐2‐phenylindole) and mounted on glass slides for analysis. To measure axon length and compute neurite densities, images were taken using a confocal microscope (Zeiss, Axioskop 2, Germany) followed by quantification analyses using ImageJ software. The following primary antibodies (at 1/1000 dilution) were used: Rabbit Anti‐Microtubule‐Associated Protein 2 (Millipore, Cat. #: AB5622), Mouse Anti‐Tau‐1 (Millipore, Cat. # MAB3420). The secondary antibodies used: Alexa‐Fluor 488 goat anti‐rabbit (ThermoFisher, Cat. # A11034), and AlexFluor 568 Donkey anti‐mouse (ThermoFisher Cat. # A10037).