Trypan Blue (TB, Sigma-Aldrich; 0.08% in 70 μl of B1), a dark blue vital stain that enters a cell only if the plasmatic membrane is porated or damaged. It was used when applying protocol P1, to verify the reliability and selectivity of electroporation with capacitive microelectrodes. Before applying the stimulus, TB was incubated 1 min on the cell culture to detect any damaged cell. Twenty minutes after the electroporation, the TB solution was removed, the cells rinsed thrice with PBS and the result checked at the microscope;
pcDNA3.1(-)EYFP/ECFP (2 μg in in 70 μl of B1), with cloned Enhanced Yellow Fluorescent Protein (EYFP) or Enhanced Cyan Fluorescent Protein (ECFP) gene49 (link). Plasmids were delivered to the cells by means of protocol P2. After the electroporation, the plasmid solution was incubated twenty minutes on the cells, then the culture was rinsed thrice with PBS and put in the incubator with the appropriate sterile complete medium. The expression of the fluorescent protein EYFP or ECFP was verified 24 or 48 h after the electroporation.
