Concentration-dependent Aβ aggregation.

<p>(A) Various concentrations of Aβ₄₂ and 30 nM QDAβ were incubated in a 1536-well plate at 37 ^°C for 24 h. Each well was observed using an inverted fluorescence microscope using a 4x objective. (B) Variations of fluorescence intensities of 10,000 pixels (100 × 100 pixel) in the center region of micrographs were estimated as SD values, the mean values were plotted against the concentrations of added Aβ₄₂. A linear equation and R² in B were determined using the data of less than 30 µM of Aβ concentrations. Error bars represent ±SDs of the mean values of fluorescence intensities (n=3 separate experiments).