Electroporation protocol

Cells were collected by trypsinization and centrifugation, washed in ice-cold electroporation buffer (125 mM sucrose, 10 mM K₂HPO₄, 2.5 mM KH₂PO₄, 2 mM MgCl₂ × 6 H₂O) and prepared for electroporation as previously described⁴⁵. Briefly, 50 μl of the suspension (1 × 10⁶ cells) served as a control for treatment, while an additional 50 μl was pipetted between two stainless-steel parallel-plate custom-made electrodes (2 mM apart), and 8 square-wave electric pulses (1300 V/cm, 100 μs, 1 Hz) were generated with an electric pulse generator GT-01 (Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, SI). Pulses were monitored on an oscilloscope Tektronix TDS3012 (Tektronix). After application of electric pulses, cells were transferred to a 24-well ultra-low attachment plate and incubated for 5 min at room temperature, then 1 ml of culture medium was added to the cells, and the cells were utilized in the different assays (see below).