Antibiotic Solutions

Antibiotic Solutions

Stock Solution (mg/mL) Storage Working Conc (µg/mL) Mode of Action Stability Storage and Handling
Ampicillin 50–100 in H2O –20oC 20 (stringent plasmids), 50–100 (relaxed plasmids) Bactericidal. Inhibits cell-wall synthesis by interfering with peptidoglycan cross-linking. Ampicillin is used with all plasmids carrying the beta-lactamase gene (bla) (e.g. pUC19, pBluescript, pGEM). 60 Days Observed half-life life of 30 days (concentration decreases)
Carbenicillin 50–100 in H2O –20oC 20 (stringent plasmids), 50–100 (relaxed plasmids) Bactericidal. Carbenicillin is a synthetic analog of Ampicillin. Inhibits cell-wall synthesis by interfering with peptidoglycan cross-linking. Carbenicillin is used with all plasmids carrying the beta-lactamase gene (bla). Unlike ampicillin, it is not subject to the formation of satellite colonies. Data indicates greater heat stability in LB and TB. under 100 (mg/mL) = 45 Days, Over 100 (mg/mL) = 60 Days Observed half-life life of 30 days (concentration decreases)
Chloramphenicol 34 in Ethanol (or Methanol) –20oC 25 (stringent plasmids), 170 (relaxed plasmids) Bacteriostatic. Inhibits translation by blocking peptidyl transferase on 50S ribosome. At higher conc, can inhibit DNA synthesis. Product of cat gene, Chloramphenicol acetyltransferase inactivates chloramphenicol. 135 days Toxic, potential carcinogen, handle powder with gloves. Store solutions at 4o°C, away from direct light. Will yellow upon degradation.
D-Cycloserine 10 in 0.1 M Sodium phosphate buffer, pH 8.0 –20oC 200 Bactericidal. D-Cycloserine only kills growing E.coli. It inhibits cell wall synthesis by preventing formation of D-alanine from L-alanine and formation of peptide bonds involving D-alanine. Mutations destroy the D-alanine transport system. 135 days
Gentamicin (also commonly, but incorrectly, referred to as Gentamycin) 10 in H2O –20oC 15 Bactericidal. Inhibits protein synthesis by binding to the L6 protein of the 50S ribosomal subunit. Aminoglycoside acetyltransferase and aminoglycoside nucleotidyltransferase inactivates gentamicin; mutations in rplF (encodes the L6 protein) prevents the gentamicin from binding. 135 days
Kanamycin 10–50 in H2O –20oC 10 (stringent plasmids), 50 (relaxed plasmids) Bactericidal. Broad spectrum antibiotic that binds to 70S ribosome. Inhibits growth of gram-negative, gram-positive and mycoplasmas. Inhibits protein synthesis, inhibits translocation, and elicits miscoding. Aminoglycoside phosphotransferase, also known as neomycin phosphotransferase, aminoglycoside acetyltransferase, and aminoglycoside nucleotidyltransferase, inactivates kanamycin. 150 days Store at 4°C away from heat and light.
Nalidixic Acid ? in H2O; adjust to pH 11 with NaOH –20oC 15 Bacteriostatic, Bactericidal at higher concentrations. A broad spectrum antibiotic. A synthetic quinilone that inhibits DNA gyrase-dependent activities such as DNA polymerization and supercoiling. Mutations in the host DNA gyrase prevents nalidixic acid from binding. 150 days
Rifampicin 34 in Methanol –20oC 150 Bactericidal. Rifampicin strongly inhibits RNA synthesis by binding to prokaryotic RNA polymerase and to a lesser extent, mammalian RNA polymerase. Sensitivity is dominant and resistance is recessive. Mutations in RNA polymerase prevents rifampicin from complexing. 150 days
Spectinomycin 10 in H2O –20oC 100 Bacteriostatic. Spectinomycin is an aminocyclitol antibiotic, closely related to the aminoglycosides. Spectinomycin binds to the 30S ribosome and translation by interfering with the translocation of peptidyl tRNA from the A site to the P site. Mutations in rpsE prevent spectinomycin binding to the ribosome. Sensitivity is dominant and resistance is recessive. 90 days
Streptomycin 5–15 in 70% Ethanol –20oC 10 (stringent plasmids), 25–50 (relaxed plasmids) Bactericidal. Inhibits protein synthesis by binding to the S12 protein of the 30S ribosomal subunit and inhibiting proper translation. Streptomycin is used in combination with Penicillin in mammalian culture to prevent bacterial infection. Resistance is due to mutations in rspL. 90 days Store at 4°C away from heat and light.
Tetracycline 5–15 in 70% Ethanol –20oC 10 (stringent plasmids), 12–75 (relaxed plasmids) Bacteriostatic. Tetracycline inhibits protein synthesis by preventing binding of aminoacyl tRNA to the ribosome A site. Resistance conferred by tetA or tetC, both result in active efflux of drug from cell. 90 days Tetracycline is inactivated by heat and light. Store away from direct light.
Zeocin 100 in H2O –20oC 20–1000 Bactericidal. Zeocin intercalates into DNA, causing double-strand breaks which result in cell death. A broad-spectrum antibiotic that is effective in most bacteria, yeast, plants, filamentous fungi and eukaryotic cells. Resistance is conferred by product of ble, the bleomycin resistance gene found on Tn5 transposon of E. coli. 60 days Store away from direct light.