Technical Advantage:  Effective against Gram-positive and -negative bacteria Ciprofloxacin Hydrochloride (HCl) is a 4-fluoroquinolone antibiotic often used to control mycoplasma contamination in infected cell lines.  It works by interfering with the bacterial enzyme DNA gyrase, which is necessary for bacterial synthesis, replication, and transcription in both the active and non-active growth phases of the bacterial life cycle.  Ciprofloxacin HCl is effective against a wide range of Gram-positive and Gram-negative bacteria and is offered in powder form. Technical Advantage:  Effective against Gram-positive and -negative bacteria Ciprofloxacin Hydrochloride (HCl) is a 4-fluoroquinolone antibiotic often used to control mycoplasma contamination in infected cell lines.  It works by interfering with the bacterial enzyme DNA gyrase, which is necessary for bacterial synthesis, replication, and transcription in both the active and non-active growth phases of the bacterial life cycle.  Ciprofloxacin HCl is effective against a wide range of Gram-positive and Gram-negative bacteria and is offered in powder form.