Ciprofloxacin HCl is a second generation fluoroquinolone antibiotic.

Fluoroquinolone antibiotics target bacterial DNA gyrase, an enzyme which reduces DNA strain during replication. Because DNA gyrase is required during DNA replication, subsequent DNA synthesis and cell division is inhibited.
Ciprofloxacin is a broad spectrum antibiotic targeting a wide variety of gram

positive and gram negative bacteria. Many mycoplasma strains, inclusive A. laidlawii, M. orale, M. hyorhinis, M. fermentas, and M. arginine, react sensitive to ciprofloxacin. Since these strains are responsible for most of the contaminations in cell culture, it can be used for removal of mycoplasma contamination. At the recommended concentration of ca. 1 µg/ml no cytotoxic effects occur.
Ciprofloxacin HCl is freely soluble at 35 mg/ml.

1. Wolfson, John S., & Hooper D. C. (1985) Am. Soc. for Microbiol. 4th ser. 28, 581 - 86