Nuclear extract from the SFN-treated as well as untreated cells were assayed for DNMT activity using a colorimetric DNMT activity assay kit (Epigentek, Brooklyn, NY) according to the manufacturer's instruction.
The enzyme activity was measured using a colorimetric PAD activity assay modified from Knipp and Vasak.
Caspase-3 activity was calculated using a colorimetric caspase-3 Activity Detection Kit (Millipore, Billerica, MA, USA), as previously described.
Caspase-1 activity in the supernatant was determined using a colorimetric caspase-1 activity assay kit (R&D Systems).
Using a colorimetric caspase-3 activity assay and immunostaining for cleaved caspase-3, we observed a concomitant increase in caspase-3 activity in cells exposed to both the toxic agents, which was significantly higher than the caspase-3 activation with either agent alone, substantiating our previous data of enhanced apoptosis in the cells subjected to co-exposure of Tat and morphine.
We also investigated the apoptotic effect of the HFB on the SAOS-2 cells by measuring the activity of caspases, using a colorimetric caspases kit that measures the activity of caspases-3 in the samples grown in the HFB for 5 days and treated with 10 µg/mL of CDDP for 24 hours.
We have also investigated this phenomenon by measuring the activity of caspases by using a colorimetric caspases kit that measures the activity of caspases-3 in the samples.
Degranulation was assessed by β-hexoseaminidase activity using a colorimetric substrate assay as previously described [47].
Transfection efficiency was normalized by assaying for β-galactosidase activity using a colorimetric method (Stratagene, La Jolla, CA) as previously described [30].
Nuclear extract (20 µg) from the SFN-treated as well as untreated cells were assayed for HDAC activity using a colorimetric HDAC assay kit (Active Motif, Carlsbad, CA) according to the manufacturer's instruction.
