Label-free Real-time Cytotoxicity Assessment

For label-free real-time cytotoxicity assessment, the xCELLigence device, an impedance-based Real Time Cytotoxicity Analyzer (RTCA) (ACEA Biosciences Inc.) that allows continuous assessment of cell growth and cytolysis was used.^{47 (link)} The adherent growing neuroblastoma cell line LS was plated at 30.000 cells per well in RPMI 1640-based complete media (see above) in 96-well electronic microtiter plates E-Plate® 96 (ACEA Biosciences Inc.). After cell attachment for 24 h to achieve a robust cell index, effector cells were added according to indicated effector to target ratio. The total volume per well was 200 µl. Therapeutic antibodies (AMs) were used at indicated concentrations. Plates were incubated in a HERAcell incubator (Heraeus) under 37°C, 95% humidity, and 5% CO₂ and impedance was assessed every 15 min for 24 h.