Figure 4.

The Matador assay is a single step homogenous assay. K562 cells stably expressing Gluc were co-cultured with NK92MI in a 24-well plate at an Effector:Target (E:T) ratio of 0.5:1 for 4 hours. Post-incubation, the cells were mixed well, collected in a 1.5 ml microfuge tubes and divided into 3 parts. (A) (Total/homogeneous), the cells along with supernatant were directly assayed for luciferase activity by plating in a 384-well plate. (B) (Cell free supernatant), cells were centrifuged and cell supernatants alone were collected in a new tube and plated in a 384-well plate, followed by measurement of the luciferase activity. (C) (Cells Pellet), cells were centrifuged, supernatant was removed, cell pellets were resuspended in PBS and plated in a 384-well plate to measure luciferase activity. Total reaction volume plated in 384-well plate for all 3 parts was kept constant at 50 µl per well and 15 µl of coelenterazine assay buffer was added in well mode to measure luciferase activity. The three figures are from a single experiment and therefore the values can be compared across the three figures for comparison. The values shown are mean ± SE of a representative experiment performed in triplicate. Statistically significant difference is shown by asterisks (****) at a level of P < 0.0001. Statistical differences shown are between K562 + Media vs K562 + NK92MI.