CytoTox-Glo Cytotoxicity Assay
The CytoTox-Glo Assay is a luminescent cytotoxicity assay that measures the relative number of dead cells in cell populations. The CytoTox-Glo Assay measures the extracellular activity of a distinct intracellular protease activity (dead-cell protease) when the protease is released from membrane-compromised cells. A luminogenic cell-impermeant peptide substrate (AAF-aminoluciferin) is used to measure dead-cell protease activity. The liberated aminoluciferin product is measured as glow type luminescence generated by Ultra-Glo Recombinant Luciferase provided in the assay reagent. The AAF-aminoluciferin substrate cannot cross the intact membrane of viable cells and does not generate any appreciable signal from the live-cell population. The amount of luminescence directly correlates with the percentage of cells undergoing cytotoxic stress. With the addition of a lysis reagent (provided), the CytoTox-Glo Assay also can deliver the luminescent signal associated with the total number of cells in each assay well. Viability can be calculated by subtracting the luminescent dead-cell signal from the total luminescent value, thus allowing you to normalize assay data to cell number and mitigate assay interferences that may lead to erroneous conclusions. The cytotoxicity protease biomarker is constitutive and conserved across cell lines, and the CytoTox-Glo Assay demonstrates excellent correlation with other methods of assessing cell viability.