Choosing a cell viability or cytotoxicity assay from among the many different options available can be a challenging task. Includes information on: Establishing an In Vitro Model System; Choosing an Endpoint to Measure; Characterizing Assay Responsiveness; Determining Dose and Duration of Exposure; Homogeneous Assays for Multiwell Formats and Automated Screening; Additional Factors to Consider When Choosing a Cell Viability Assay; Cell Viability Assays that Measure ATP Protocol; etc..