Figure 3. The uptake of microinjected synthetic sAβ by microglia was measured by flow cytometry.

(A-C) Five days after surgery, adult primary microglia were isolated and stained with PE-Cy7-CD11b and APC-CD45. The CD11b⁺/CD45^low microglia were gated and the percentage of Aβ⁺ cells among those gated microglia was analyzed. Representative Aβ⁺/CD11b⁺/CD45^low microglia were recorded in the control group microinjected with fluorescence-labeled scrambled peptide (A) and in the treatment group microinjected with FLsAβ₄₂ (B). (C) The percentage of Aβ⁺/CD11b⁺/CD45^low microglia in both groups was analyzed (n= 5 females per group); p < 0.05 (nonparametric Mann Whitney test). Detailed statistical results are shown in Table 2. Only a very small fraction (less than 1.5%) of microglia in the FLsAβ₄₂-treated group were Aβ-positive.