The implementation of LDH assays for cytotoxicity testing in HTS has been historically limited because most commercial assay protocols require a cell-free sample transferred into a separate assay plate. Reagents that are compatible with viable cells are available to detect release of LDH, thus enabling a single addition homogeneous assay format [45] . Now LDH release can be routinely measured in HTS formats after a short incubation (10-20 minutes) using a fluorometer equipped with a 560nm excitation source and a 590nm collection filter (Fig. 3 ) [46] . LDH assay detection is a robust and cost-effective means of assessing cytotoxicity, but is susceptible to background 