This β-lactam antibiotic is a derivative of penicillin that inhibits cell wall synthesis. It is most active against Gram-negative bacteria and is bactericidal to growing Escherichia coli. Resistance is mediated by ampicillin β-lactam ring cleavage by the β-lactamase enzyme. It is recommended for antibacterial use in cell culture media and selection of resistant bacteria, and it is used as a selective agent for plasmid transformation, such as pBR322 and pUC derivatives.
White to off-white
1 M HCl (50 mg/ml) H2O: 10 mg/ml Slightly soluble in ethanol. Insoluble in ether, benzene, chloroform, ethyl acetate, and petroleum ether.