SNU-5 (1750 cells/well, 12.5 uL), A549 cells (750 cells/well, 12.5 uL), HT-29 (1000 cells/well, 12.5 uL) and SK-BR-3 (1000 cells/well, 12.5 uL) were seeded in a white flat-bottom 384-well plate (3570, Corning) at least 4-8 h before drug treatment for SNU-5 and 16-24 h for all the adherent cells. 2× working stock of the anti-cMET FDC (200 nM) or ADC (20-200 nM) were initially prepared in the cell growth media which were subsequently serially diluted in the corresponding media 3-fold. Following this, 12.5 uL of each of the serially diluted drug conjugates were added into the 384-well plate containing the cells. In a similar manner, replicates of 12.5 uL each of either a 2 uM Staurosporine (S1421, Selleck Chemicals) or media only was added into the wells to serve as the 100% cell killing and 0% cell killing, respectively. For the combination treatment, cells were treated with a 3-fold serial dilution of the anti-cMET IgG starting at 50 nM (final concentration in the well) while holding the FDC concentration constant at the approximate IC50 of 2 nM. After 96 h incubation at 37°C with 5% CO2, 25 uL of room temperature CellTiterGlo2.0 reagent (G9241, Promega) was added to each well using a multichannel pipette followed by a 2-min shaking using an orbital shaker (500 rpm), and then a 10-min incubation at room temperature. Afterwards, the plate was read using plate reader capable of reading luminescence in multi-well plates (Tecan Spark). Data were analyzed using GraphPad Prism software.