Live/dead staining.

Live/dead staining with Calcein-AM and EthD-1 of human normal dermal fibroblast, colon cancer, and bladder cancer spheroids 4 days after treatment with 168 mM calcium (Ca), 1 mM bleomycin (Bleo), electroporation (EP; 8 pulses of 100 μs, 1000 V/cm, and 1 Hz), 168 mM calcium electroporation (Ca EP), or electrochemotherapy using 1 mM bleomycin (Bleo EP), and of untreated controls (Control). Upper panels are calcein-AM staining (living cells), middle panels are EthD-1 staining (dead cells), and lower panels are merged images of living (green) and dead (red) cells.