Fig. 2.
Cold target inhibition assay of the killing of K562 cells by K562 and ML-2 cells.
NK cells and DiO-labeled K562 cells (ratio 20:1) were coincubated with nonlabeled K562 or ML-2 cells in various concentrations. After an incubation time of 4 hours, the dead cells were stained with PI and analyzed by flow cytometry.