The CytoTox-ONE Homogeneous Membrane Integrity Assay is a fluorometric method for estimating the number of nonviable cells present in multiwell plates. The CytoTox-ONE Assay rapidly measures the release of lactate dehydrogenase (LDH) from cells with a damaged membrane. LDH released into the culture medium is measured with a 10-minute coupled enzymatic assay that results in the conversion of resazurin into a fluorescent resorufin product. The amount of fluorescence produced is proportional to the number of lysed cells using a 96- or 384-well format. The CytoTox-ONE Reagent does not damage normal healthy cells; therefore the reactions to measure released LDH can be performed directly in a homogeneous format in assay wells containing a mixed population of viable and damaged cells. The CytoTox-ONE Homogeneous Membrane Integrity Assay, HTP (Cat.# G7892), offers convenient, alternative packaging for processing multiple plates. Each bottle of reagent supplied with the system is sufficient to perform 500 assays in a 96-well format or 2,000 assays in a 384-well format when the recommended volumes are used.