The MD Anderson Cancer Center worked in collaboration with Nexcelom to create a new method by which to measure the cytotoxic potential of natural killer (NK) cells. The traditional non-radioactive method, calcein release, is subject to variation, with differing dynamic ranges depending on tumor type. The Cellometer Vision and calcein, in combination with K562, 721.221, and Jurkat cells, were used to develop a novel, image cytometry-based assay to ascertain NK cytotoxicity. Using fluorescent intensity gating to ignore dimmer cells and apoptotic bodies, image cytometry provided a way to measure tumor cell lysis in a specific manner with the same experimental [...]