Cell extracts from African green monkey kidney (CV-1) cells, stably expressing human four repeat tau and a protein phosphatase inhibitor, were resolved by SDS-PAGE on a 10% Tris-glycine gel. The proteins were transferred to nitrocellulose. Membranes were incubated with 0.50 µg/mL ab4842, following prior incubation in the absence (1) or presence of the peptide immunogen (2), the non-phosphopeptide corresponding to the tau phosphopeptide (3) or a generic phosphothreonine peptide (4). After washing, membranes were incubated with goat F(ab’)2 anti-rabbit IgG alkaline phosphatase and bands were detected using the Tropix WesternStar detection method. The data show that only the phosphopeptide corresponding to this site blocks the antibody signal, illustrating the specificity of ab4842 antibody for this phosphorylation site. (B – secondary alone.)

WB using ab4842. The peptide corresponding to tau [pT212] blocks the antibody signal, thereby demonstrating the specificity of the antibody.