Used primarily as an antibacterial agent in laboratory settings, particularly in cell culture and microbiological media preparation. It serves as a selective agent to inhibit the growth of unwanted bacteria, allowing for the isolation or maintenance of specific microbial or cell lines that are resistant to sulfonamides. Commonly included in selective media for hybridoma selection and in molecular biology applications where antibiotic selection is required. Its sodium salt form improves solubility in aqueous solutions, making it suitable for use in liquid media and sterile filtration processes.