Characterization of the specificity of novel tau monoclonal antibodies by ELISA.

(A) Sequences of the peptides used in attempts at generating tau monoclonal antibodies, as well as the corresponding amino acid sequences from full-length human and murine tau. T169 and T175 are represented with orange text. The overlapping region between the 163–179 peptide antigen and the actual tau sequence is underlined in red. Single amino acid differences between human and murine tau are highlighted in yellow. (B-D) ELISA data from experimental antibodies MHT1 and MHT2, as well as the well-characterized PHF1 antibody, respectively, as indicated above each graph. The ELISA plates contained triplicate sets of various phosphorylated peptides representative of different threonine epitopes on tau, as well as non-phosphorylated counterparts for each peptide. A truncated, C-terminal tau species (244–441) was also used as a control, with one batch of the C-terminal protein having been phosphorylated by GSK3β. Recombinant, full-length 2N4R tau protein was also used.