I’m facing recurring contamination in my HL-1 cell cultures while using a C-PACE EM system. I suspect the issue comes from the fact that the multiwell plate doesn’t seal tightly when the electrodes are inserted. I’ve tried sealing with parafilm but still got E. coli contamination. I also alyways strerilize the elctrodes using ethanol and treat them with UV light. Has anyone else experienced this issue, and how did you solve it? How do you ensure sterility when using electrodes in culture plates, and does anyone have specific suggestions for sealing methods?