Figure 6.
Competition with unlabeled Aβ42 protofibrils does not significantly reduce internalization of AF488-Aβ42 protofibrils. Panel A. Primary microglia were treated with solution mixtures of AF488-labeled (L) and unlabeled (U) Aβ42 protofibrils at the concentrations depicted for 15 min at 37 °C. Cells were fixed, stained with DAPI (blue), and imaged (40X magnification) as described earlier in Fig 1. Panel B. In a separate set of experiments (n=2), primary microglia were treated with lower concentrations of AF488-labeled Aβ42 protofibrils (5 µM) for 10 min at 37 °C. Ratios depicted in panel B are in µM. Confocal images were obtained and uptake (fluorescence intensity) was quantified using ImageJ as previously described.