Cell proliferation and viability assessment
Cell proliferation was assessed using Alamar Blue (Thermo Scientific) and CFSE
(Invitrogen) labeling following manufacturer’s instructions. Briefly, the assays were
performed at the end of the culture experiments. Alamar Blue was added to culture medium
(100 μl/ml of medium) and incubated for 6 h. Fluorescence was monitored at 530–560 nm
excitation wavelength and 590 nm emission wavelength in a 96 well plate using a
fluorescence multiplate reader (FLUOstar OPTIMA, BMG LABTECH). For CFSE labeling,
cultures were treated with 1 μM CFSE in pre-warmed PBS for 15 min at 37°C. Labeling
solution was replaced by pre-warmed culture medium, and cells were cultured for 30 min at
37°C to allow acetate hydrolysis. Cells were washed, incubated for different time points and
analyzed using a FACScan flow cytometer (Becton Dickinson).
For the analysis of apoptosis, we used AnnexinV / 7-AAD labeling. Dissociated cells were
resuspended in AnnexinV binding buffer, and stained with FITC-AnnexinV (PharMingen).
Just before cell acquisition, 5 μl of 7-AAD was added and cells were acquired in a FACScan
flow cytometer (Becton-Dickinson).