The ApoLive-Glo™ Multiplex Assay measures both the number of viable cells as a marker of cytotoxicity and caspase activation as a marker of apoptosis within a single assay well to determine the mechanism of cell death. The first part of the assay measures the activity of a protease marker of cell viability. The live-cell protease activity is restricted to intact viable cells and is measured using a fluorogenic, cell-permeant, peptide substrate (glycyl-phenylalanyl-amino fluorocoumarin; GF-AFC). The substrate enters intact cells, where it is cleaved by the live-cell protease activity to generate a fluorescent signal proportional to the number of living cells. This live-cell protease becomes inactive upon loss of cell membrane integrity and leakage into the surrounding culture medium. The second part of the assay uses the Caspase-Glo® Assay technology to detect caspase activation, a key biomarker of apoptosis. The Caspase-Glo® Assay provides a luminogenic caspase-3/7 substrate, which contains the tetrapeptide sequence DEVD, in a reagent optimized for caspase activity, luciferase activity and cell lysis. Adding the Caspase-Glo® 3/7 Reagent in an 'add-mix-measure' format results in cell lysis, followed by caspase cleavage of the substrate and generation of a 'glow-type' luminescent signal produced by luciferase. Luminescence is proportional to the amount of caspase activity present.
Features - Benefits
Measure Viability and Apoptosis in the Same Sample Well: Accurately determine the mechanism of cell death in less time with less sample.
Easy to Implement: The assay uses a simple sequential 'add-mix-measure' format.
Normalize Caspase Data with Viability Control: The ratio of caspase activity to viable cell is useful for determining the extent of caspase activation and for normalizing cell numbers.
Flexible and Easily Automated: The volumes of each assay component can be scaled to meet throughput needs, and the assay is amenable to automation in 96- and 384-well plates.
Reveal cell death even if the window of caspase activity is missed.
Multiplex with Other Assays: The nonlytic nature of the first step of the assay allows further multiplexing with spectrally distinct fluorescent assay chemistries.
Applications
Determine mechanism of cell death.
Profile compounds for cytotoxic risk.