Abstract: A high-throughput live whole cell assay method involves measuring the effect of one or more test compounds on a characteristic, e.g., growth, of a cell culture in a multi-well vessel at one or more timepoints during the growth of these cells in culture, after the cells are contacted with the compound. This assay format permits the identification of test compounds that have an inhibitory or stimulatory effect, among others, on cell growth at different times during the growth phase of the cells. It has the advantages of using small volumes which make the assay suitable for automation and enables detection of test compounds with the desired effect that are often missed by conventional assays which assess test compound activity at a single timepoint.