Cell viability and proliferation assays are a fundamental tool in the drug discovery process. They are used to evaluate both the potency of compounds, as well as their toxicity profiles for drug safety assessments. Many commonly used plate reader assays (e.g. ATP-luminescence measurements) assume a linear relationship between the assay signal, the number of cells and their viability. However, as this poster illustrates, this assumption is not always justified: ATP-luminescence measurements can significantly overestimate toxicity and underestimate potency, leading to false-negative viability/efficacy hits.
Here we show the development and implementation of an alternative no-wash HCA assay, which eliminates common problems associated with ATP-luminescence measurements. We compare the drug-responses of several well-characterised anti-cancer drugs on HeLa cells, measured by both the HCA assay and a commercial ATP-luminescence detection system, and highlight key differences between the measurements.