The most commonly used method for elimination, inactivation, or suppression of mycoplasmas in cell cultures is treatment with distinct antibiotics. In general, antibiotic therapies do not result in long-lasting, successful elimination. Also, the cytotoxic properties of antibiotics can cause undesirable side effects on eukaryotic cells and may facilitate the development of resistant mycoplasma strains. The new Mycoplasma-EX method for mycoplasma elimination overcomes all of these drawbacks combining a non-antibiotic and a thoroughly adjusted antibiotic treatment resulting in unique features as compared to other methods and products. Mycoplasma-EX is the first biological reagent that quickly eliminates mycoplasmas by directly killing them, and not just by inhibiting their growth. It is the only anti-mycoplasma agent that can be used to clean most eukaryotic cell lines and primary cells as well as virus stocks fast and directly while showing an extremely low cytotoxicity.