Cell-mediated cytotoxicity is an important phenomenon characterized by cytolysis of a compromised cell in the body by immune system. Activation of immune system leads to removal of target cells infected by pathogens or transformed cells/cancer cells. This process is mediated by antibody-dependent cell-mediated cytotoxicity (ADCC), complement-mediated cytotoxicity, or lymphocyte-mediated cytotoxicity. Assay Genie's Cell-Mediated Cytotoxicity Assay Kit contains carboxyfluorosuccinimide ester (CFSE), a green fluorescent probe that labels live target cells and 7-aminoactinomycin D (7-AAD), a red fluorescent probe that labels late apoptotic and necrotic target cells killed in the cytotoxicity assay. This assay does not require cell lysis and provides a direct measurement of cytotoxicity instead of indirect indicators such as release of ATP or lactate dehydrogenase activity. The flow cytometry-based method provides robust data and enables multi-parametric analysis.