Zeocin is a trade name for a formulation of phleomycin D1, a glycopeptide antibiotic and one of the phleomycins from Streptomyces verticillus belonging to the bleomycin family of antibiotics. It is a broad-spectrum antibiotic that is effective against most aerobic organisms including bacteria, filamentous fungi, yeast, plant, and animal cells. It causes cell death by intercalating into DNA and inducing double stranded breaks of the DNA.