Ampicillin is a semi-synthetic derivative of penicillin, active as a broad-spectrum antibiotic. It is inactivated by beta-lactamases and for this reason a beta-lactamase inhibitor should be considered when using ampicillin. Against gram-positive bacteria, ampicillin has a similar mode of action as benzylpenicillin; against gram-negative bacteria, it has a similar mode of action as chloramphenicol and tetracyclines. In E. coli it inhibits cell wall synthesis.
Ampicillin is used to select bacteria cells with specific resistance during general microbiology studies. It is used to study antibiotic resistance and penetration limitations, the synergy between multiple antibiotics, certain bloodstream infections, and has been used to develop PCR assays to detect resistance genes in cerebrospinal fluid.
Ampicillin is a β-lactam antibiotic with an amino group attached to the penicillin structure. Inhibits bacterial cell-wall synthesis (peptidoglycan cross-linking) by inactivating transpeptidases on the inner surface of the bacterial cell membrane. Bactericidal only to growing Escherichia coli. Mode of resistance: Cleavage of β-lactam ring of ampicillin by β-lactamase. Antimicrobial spectrum: Gram-negative and Gram-positive bacteria.
Grade: Anhydrous
Key Applications: Antibacterial, Antibiotics
Product Type: Biochemicals
Biochemical Category: Antibiotics
Melting Point: 208°C decomposes
Presentation: White Powder
Format: White Powder
pH: 4.51 (Lit.)
pKa: pKa = 2.5 (-COOH) pKa = 7.3 (-NH2) at 25°C
Water Content: <1%
Solubility: Soluble in 1 M Ammonium Hydroxide (50 mg/mL), dilute acids or bases; slightly soluble in water; practically insoluble in alcohol, chloroform, ether and fixed oils.
Storage & Handling: Store at +4°C.