2.12. Caspase 3/7, 8 and 9 assays
Caspase activity was measured by using Caspase-Glo
3/7, 8 and 9 assay kits
(Promega Corporation, Australia). Briefly, SK-MEL-28 and A-431 cells (110
4
cells/well) were seeded in a luminometer plate and incubated for 24 h at 37C. Cells
were then treated with different concentrations of individual compounds for 48 h.
To each well, 50ll of caspase-3/7, -8 or -9 reagents were added and the luminescence was recorded every 15 min for 1 h at 28C in a microplate reader (Synergy
4, Bioteck, Millennium Science).
Prior to the Caspase assay, cell number in the same well after treatment was
measured by the Cell Titer Blue assay (Promega Corporation, Australia) to normalize
the result. Briefly, 10ll of the staining was added to each well and incubated for 1 h
at 37C. The fluorescence was recorded at 560(excitation)/590(emission) in a
microplate reader.
The results are presented as relative luminescence unit (RLU)/cell/min.