Elimination of mycoplasma contamination of virus stocks

We studied the effectivity of a commercial antibiotic kit Mycokill AB for the elimination of mycoplasma contamination in virus strains. The contaminated virus strains were first filtered, treated with Mycokill AB for three hours and repeatedly passaged in its presence in the cultivation medium in pure cell lines. Three passages in the presence of Mycokill AB were invariably followed by three passages without Mycokill AB. The effectivity of purification was then checked by PCR. Twenty-four out of 28 tested virus strains became free of mycoplasma after a first or second cycle of the treatment with Mycokill AB. The other four strains remained positive even after repeated passages. In these cases of a likely resistance to Mycokill AB, we managed to eliminate the mycoplasma contamination through a subsequent treatment with the antibiotic combination BM-Cyclin. Mycokill AB was shown in the elimination of mycoplasma from virus suspensions as successful as other known most effective antibiotics.