Figure 2. Aβ levels in APP/PS1 mice. For Aβ analysis, blood samples were individually collected from 4Aβ1-15, Aβ42 or PBS immunized APP/PS1 mice at the time points indicated. (A) Serum Aβ40 (B) Aβ42 peptides were measured separately by Aβ ELISA. Data were presented as mean ± SD of Aβ40 or Aβ42 (pg/ml). The Aβ levels of both 4Aβ15 (n = 9, ^*P< 0.01) and Aβ42-treated (n = 9, ^#P <0.01) group were increased compared with the control group. Detergent-soluble Aβ40, Aβ42 peptides (C) and insoluble Aβ40, Aβ42 prepared from 5M guanidine extraction (D) were separately measured in brain homogenates by ELISA. Data were presented as mean ± SD of Aβ40 or Aβ42 (pg/mg protein), and reductions for each group are indicated.