Cayman’s 7-AAD/CFSE Cell-Mediated Cytotoxicity Assay Kit employs CFSE to label target cells within the mixed cell population and 7-AAD to label dead cells. This kit provides an improvement over the traditional 51chromium (51Cr) release assay to assess cell-mediated cytotoxicity. CFSE labeling is more sensitive, does not employ radioisotopes, and cytolysis can be assessed at the single-cell level. The mixed lymphocyte reaction is a cornerstone method of immunology, and this kit can help immunologists to detect subtle changes in cytotoxic lymphocyte function. The kit provides sufficient reagents to effectively stain approximately 109 cells.