In vitro cytotoxicity testing technologies for HTS continue their refinement on many fronts. High Content Screening (HCS) and label-free methods have gained some degree of popular following recently, but require expensive instrumentation, complicated analysis software packages and offer relatively low throughput. With burgeoning costs associated with drug discovery efforts, straight-forward, validated, homogeneous assay chemistries remain the choice as a simple and cost-effective means of assessing cytotoxic burden. A. 