NK Cell Isolation and Cytotoxicity by Radioactive Chromium Release Assay and DELFIA-EuTDA Cytotoxicity Assay

Cytotoxicity assays are important in vitro tools to measure the lysis of desired target cells via an effector immune cell of choice. Specific lysis of the target cells can be determined by labeling the target cells with a radioactive isotope or fluorescent molecule, co-incubating it with an effector cell, then measuring the release of the labeled molecule in the supernatant. Here, we describe and compare different cell cytotoxicity assays using a chromium-51 (⁵¹Cr) release and DELFIA EuTDA fluorescent assay using K562 as the target cells and peripheral blood mononuclear cell (PBMC) derived natural killer (NK) cells as the effector cells.