96-well microtitre plates were coated overnight at 4°C with recombinant human beta amyloid (4-15), beta amyloid nY10 (4-15), and beta amyloid nY10 (1-42), in duplicate at a concentration of 1µg/mL. Plates were blocked with 1% BSA in PBS-T (0.1% Tween) for 1 hour before incubation with an 8-step 2x serial dilution of ab219819 from 10 µg/mL for 1 hour at room temperature. Antibody binding was detected with Goat Anti-Rabbit IgG H&L (HRP) (ab205718) secondary antibody at a 1 in 10000 dilution for 1 hour at room temperature. Plates were incubated with TMB ELISA substrate for 7 minutes prior to being stopped with Stop solution and absorbance measured at 450nm.