Practical Molecular Biology - home page.
 > Protocols > Antibiotics.

Antibiotics.

 
    About the recalculation of recipes for the arbitrary volume:


    Working concentrations and stock solutions.

     Stock solutionWorking concentration:
    Strict controlWeak control
    mg/ml:         µg/mldilutionµg/mldilution
    Ampicillin50 (H2O*)-20oC200.4 µl/ml60-1251.2-2.5 µl/ml
    Carbenicillin50
    (H2O, 50%EtOH)
    -20oC200.4 µl/ml60-2001.2-4 µl/ml
    Chloramphenicol34
    (EtOH, MetOH)
    -20oC250.7 µl/ml1705 µl/ml
    D-cycloserine*10
    (0.1M NaP pH8.0)
    +4oC20020 µl/ml  
    Gentamycin10 (H2O)-20oC151.5 µl/ml  
    Hygromycin B10 (H2O)-20oC101 µl/ml40040 µl/ml
    Kanamicin50 (H2O)+4oC-
    -20oC
    100.2 µl/ml501 µl/ml
    Kasugamycin10 (H2O)-20oC1000100 µl/ml  
    Nalidixic acid5
    (H2O, pH to 11 /NaOH)
    -20oC153.0 µl/ml  
    Neomycin10 (H2O)-20oC10010 µl/ml80080 µl/ml
    Rifampicin**34 (MetOH)-20oC1504.4 µl/ml  
    Spectinomycin10 (H2O)-20oC10010 µl/ml  
    Streptomicin50 (H2O)-20oC100.2 µl/ml501 µl/ml
    Tetracycline***5 - 12.5
    (EtOH, 70%EtOH)
    -20oC102 µl/ml50
    100
    10 µl/ml
    20 µl/ml

    * - Unstable solution, prepare just before use;
    ** - Light sensitive;
    *** - Light sensitive, Mg2+ - inhibitor;

    Preparation of stock solutions.

    Ampicillin.

    Conc.1ml5ml10ml
    Ampicillin50mg/ml50mg250mg0.5g
    H2O 1ml5ml10ml
  • filter sterilization; or preparation from the sterile water and the sterile powder;
  • store at -20oC in small quantities (about 10 freezing-thawing cycles);
  • instead of H2O it is possible to use 50% glycerol. The advantage - solution is liquid at -20oC.
  • some laboratories use 96% (or 50%) EtOH for ampicillin solubilization. There are two advantages in this method: (i) solution is liquid at -20oC, (ii) the solution is self sterilizing. But the disadvantage it very serious: ethanol is a weak catalyst of b-lactam ring disruption. So, solution is unstable.
  • Carbenicillin.

    Conc.1ml5ml10ml
    Carbenicillin50mg/ml50mg250mg0.5g
    H2O 1ml5ml10ml
  • filter sterilization; or preparation from the sterile water and the sterile powder;
  • store at -20oC in small quantities (about 10 freezing-thawing cycles);
  • 200 µg/ml for pETpfu.
  • Chloramphenicol.

    Conc.1ml5ml10ml
    Chloramphenicol34mg/ml34mg170mg340mg
  • store dry powder at 4oC, solution at -20oC (in EtOH);
  • BL21(DE3)pLyzS - 34µg/ml -> 1µl for 1ml of medium.
  • GE antibiotic mix (50x).

    Conc.40ml
    Cefotaxime 25µg/ml25µg/ml1mg
    Ceftriaxone 25µg/ml25µg/ml1mg
    KPO4(pH 6.0) 0.1M 40ml
  • filter sterilization; or preparation from the sterile KPO4 and the sterile powder;
  • store at -200C, in small quantities (about 10 freezing-thawing cycles).
  • Tetracycline.

    Conc.1ml5ml10ml
    Tetracycline5mg/ml5mg25mg50mg
    EtOH 1ml5ml10ml
  • solution in EtOH, store at -20oC.
  • Mg++- antagonist, for the selection it is necessary to use Mg-free medium.

"Practical Molecular Biology" http://molbiol.edu.ru
e-mail: pmb@molbiol.edu.ru


Rambler's Top100