Passive immunization protects Tg2576 mice from accumulation of intraneuronal AβOs. Dot blot immunoassay for A11-immunoreactive AβOs in saline-soluble extracts (A), saline-insoluble, SDS-extractable extracts (B), and SDS-insoluble, FA-extractable extracts (C) obtained from untreated, 1A9-treated, or 2C3-treated mice (30 μg of total extracted brain protein per dot). Results from densitometric imaging of these same samples. The line indicates the mean of each set. The p value was determined by one-way ANOVA: *p < 0.05, **p < 0.001. (C) Confocal immunofluorescence microscopy images of Tg2576 mouse brain. Sections of the hippocampus of the Tg2576 mouse brain were doubly immunostained with 7-AAD (red, 1:50) and anti-A11 antibody (green, 1:250). Scale bar = 10 μm.