Bioluminescent viability test system in cell cultures for cytotoxicity assays

Abstract

In most tissue culture cytotoxicity assays ATP determination is used for the estimation of the number of viable cells. However, the ATP assessment technique itself does not necessarily reflect viability correctly because ATP turnover is extremely rapid in living cells and intracellular ATP may decrease without the ultimate death of the cells. On the other hand, cell protein changes more slowly and the ATP/protein ratio should be a better indicator for cell viability than ATP alone. In our study we worked out a model system where MDCK monolayer tissue culture cells were treated with NaF and cell viability was monitored by bioluminescent determining of ATP referred to cell protein. Our results showed a dose dependent cellular response to NaF expressed as ATP/protein ratio. We also analyzed the morphology of actin filaments by phalloidin-FITC staining. Our model seems to be more suitable for testing cytotoxic agents than ATP measurement alone.