CellTox™ Green Cytotoxicity Assay

Here, CellTox™ Green Dye was mixed with K562 Cells, which were plated, then dosed with compound. CellTiter-Glo® Cell Viability Assay Reagent was added at the end of the 72-hour exposure and luminescence (viability) measured. These two inverse measures of cell health resulted in EC₅₀ agreement.

CellTox™ Green can be used in kinetic mode to determine the onset of cytotoxicity followed by multiplexing with the Caspase-Glo® 3/7 Assay in the same sample well to confirm caspase-3/7 activation at the appropriate time.

In this example, K562 cells were exposed to Methotrexate, an anti-proliferative compound, for 72 hours. CellTox™ Green Dye was added to determine cytotoxicity, then CellTiter-Glo® Reagent was added to the same sample well for viability determination. A viability assay alone would have misreported the compound as cytotoxic due to less cells in the treated sample compared to the non-treated control, which continued to proliferate. Multiplexing with a cytotoxicity assay reveals no change in signal as a result of compromised membrane integrity, indicating growth inhibition and not cytotoxicity.