Cell count reagent sf

At 24 h after siRNA transfection, the cells were detached and seeded for a proliferation assay. Cell proliferation was evaluated using Cell Count Reagent SF (Nacalai Tesque), according to the manufacturer's protocol. The absorbance value at 450 nm was measured to determine cell viability using a plate reader (Bio‐Rad Laboratories).

100 μL aliquots of the cell suspension (5 × 10³ cells/100 μL) were dispensed into the wells of two 96 well plates (thermo scientific). After incubation of the two plates at 37 °C for 24 h in 5% CO₂, DMEM was replaced with 100 μL Hanks' balanced salt solution (HBSS; H8264, Sigma) containing Aβ40-C₆₀ and/or Aβ40, whose pH was adjusted to 8.1. The final concentration of Aβ40 in each well for the test of Aβ40 only was ∼16 μM. For the test of Aβ40-C₆₀, the final concentration of C₆₀ was 20 μM in each well. The molar absorption coefficient of C₆₀ in o-dichlorobenzene was used for evaluating the concentration of C₆₀, as mentioned above. One plate was irradiated with 30 W LED light for 2 h at 30 °C in the incubator (i.e., the photoirradiated condition), while the other plate was shaded in a box and left at 30 °C for 2 h (i.e., the dark condition). After the 2 h treatment, HBSS in each well was replaced with DMEM and the two plates were incubated for additional 18 h at 37 °C in 5% CO₂. Then, 10 μL of the solution of WST-8 dye (Cell count reagent SF, Nacalai Tesque) was added to each well and the cell viability was examined according to the protocol of the manufacturer. Absorbance at 450 nm was recorded using a plate reader (SpectraMax Paradigm, Molecular devices).