Ampicillin sodium is the sodium salt of ampicillin, a broad-spectrum beta-lactam antibiotic derived from penicillin. As a biotech-grade reagent, it is widely used in microbiological research to select for ampicillin-resistant bacterial strains in cloning and transformation experiments. In the medical field, it treats various bacterial infections caused by susceptible strains, including respiratory tract infections, urinary tract infections, meningitis, and gastrointestinal infections. It is administered intravenously or intramuscularly in hospitals for severe cases and is also used in veterinary medicine to treat bacterial infections in animals.