• Ampicillin anhydrous packaged and labeled.

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SKU: A043

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Ampicillin anhydrous is a member of the extended spectrum β-lactam family and similar in structure to penicillin. Resistance to Ampicillin is due to cells containing plasmid encoded ESBLs.

TOKU-E offers five forms of ampicillin:

In aqueous solution, ampicillin sodium is freely soluble (50 mg/mL). Ampicillin trihydrate is slightly soluble in water (10 mg/mL) and freely soluble in 1 N HCl (50 mg/mL). Ampicillin anhydrous is sparingly soluble in water and freely soluble in 1 N NH4OH (50 mg/mL). Ampicillin sodium is commonly used to select for successfully transformed bacteria. Ampicillin anhydrous (powder) is the most stable and pure form of ampicillin TOKU-E offers.

    CAS Number


    Molecular Formula


    Molecular Weight


    Mechanism of Action

    Like all β-lactams, ampicillin interferes with PBP (penicillin binding protein) activity otherwise involved in the final phase of peptidoglycan synthesis. PBP’s are enzymes which catalyze a pentaglycine crosslink between alanine and lysine residues. Without a pentaglycine crosslink, the integrity of the cell wall is severely compromised ultimately leading to cell lysis.

    Storage Conditions


    Tariff Code



    Ampicillin targets non ESBL (Extended Spectrum β-lactamase) bacteria including Staphylococcus and Streptococcus and medically important enteric pathogens such as Shigella and Salmonella. Interestingly, ampicillin has been found to be effective against certain β-lactam sensitive VRE or vancomycin resistant Enterococcus; a glycopeptide antibiotic resistant "superbug."


    Eukaryotic Cell Culture Applications

    Ampicillin is routinely used to select for cells containing the pcDNA3.1 and pEAK10 resistance plasmids in cell line A904L at an effective concentration of 50 µg/mL. For additional information on your cell culture needs, please visit our cell-culture database.

    Microbiology Applications

    Ampicillin anhydrous is often used to select for cells that have been transformed with a plasmid containing the ampR gene which confers resistance to ampicillin. Ampicillin sodium is typically used at a concentration of 50-100 µg/mL.

    Media Supplements

    Ampicillin anhydrous can be used as a selective agent in several types of isolation media:

    Aeromonas Medium Base - Ampicililn Selective Supplement





    White crystalline powder



    Water Content (Karl Fisher)



    3.5 - 5.5

    Optical Rotation

    +280° to +305°


    (On Dried Basis): ≥98.0%

    Sulfated Ash


    Heavy Metals


Technical Data
Tryptone 20.00 Sodium Chloride 0.50
Yeast Extract 5.00 Magnesium Chloride 0.96
Potassium Chloride 0.186
Final pH 7.0 ± 0.2 at 25ºC
Suspend 26.6 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent
agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at
121°C for 15 minutes. The prepared medium should be stored at 2-8°C. The color of the prepared medium is amber,
slightly opalescent.
The dehydrated medium should be homogeneous, free-flowing and beige in color. If there are any physical changes,
discard the medium.
SOB MEDIUM is a nutrient rich medium for the preparation and transformation of competent cells. The transformation
requires perforation of the bacteria to allow the introduction of alien DNA inside the cell. In order to survive this process
the competent cells need an isotonic rich medium.
Peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is source of vitamins,
particularly the B-group. Sodium chloride and Potassium chloride supplies essential electrolytes for transport and osmotic
balance. Magnesium sulfate is a source of magnesium ions.
Inoculate with the transformed cells and incubate at 35 ± 2°C for 18 - 24 hours.
The following results were obtained in the performance of the medium from type cultures after incubation at a
temperature of 35 ± 2°C and observed after 18 - 24 hours
Microorganisms Growth
  • Escherichia coli ATCC 23724 Good
  • Escherichia coli ATCC 53868 Good
  • Escherichia coli ATCC 33694 Good
  • Escherichia coli ATCC 33849 Good


    Guzmán, Flavio, MD. "Beta Lactams Antibiotics (penicillins and Cephalosporins) Mechanism of Action.” Medical Pharmacology. Pharmacology Corner, 29 Nov. 2008. Web. 21 Aug. 2012.

    Pitout JD, Sanders CC, Sanders WE Jr. Antimicrobial resistance with focus on beta-lactam resistance in gram-negative bacilli. Am J Med 1997; 103:51.

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