Enriched NK cells were incubated with CellTrace Far Red labeled THP-1 cells at a 2:1 effector to target ratio with no treatment, 30nM CLEC12A TriKE, rhIL-15 or anti-CLEC12A scFv for 48 hours within an IncuCyte S3 imager. Dead THP-1 cells were measured using a Caspase 3/7 reagent (green). (A) Quantification of the percentage of live THP-1 tumor targets (CellTrace Far Red+, Caspase 3/7-) normalized to targets alone at the 0-hour time point. Readings were taken every 30 minutes over a 48-hour period. Representative of 3 separate experiments. (B) Representative images (original magnification 34: 2.82 mm/pixel) at 0, 18, and 36 hours showing THP-1 cells (larger red cells) and NK cells (smaller black cells). Arrows point to killing clusters where dying THP-1 cells (yellow) are apparent. (C) Quantification of the percentage of live THP-1 tumor targets at different effector to target ratios (1:1, 2:1 and 5:1).