BIOMYC-3 is based on the antibiotic ciprofloxacin, which is a member of the fluoroquinolone group and inhibits synthesis of the enzyme DNA gyrase which is responsible for supercoiling in bacterial DNA. Many mycoplasma species have been found to be sensitive to BIOMYC-3, including A. laidlawii, M. orale, M. hyorhinis, M. fermentans, and M. arginini. These species are responsible for most mycoplasma contamination in cell culture. At the concentrations recommended for use, no cytotoxic effects have been found so far, and the treatment is quite easy to perform.The treatment consists of adding the antibiotic to the growth medium for 12 days, and changing the medium every three days. On completion of the treatment, the cells should be grown on media without antibiotics for at least two weeks and then re-tested for the presence of mycoplasma. If the culture tests positive, the course of treatment should be repeated. Treatment with ciprofloxacin does not damage or alter the cells. This antibiotic should not be used repeatedly in cell cultures; otherwise, the mycoplasmas are liable to develop resistance to it.