抗生素溶液配制

抗生素溶液配制

* - Unstable solution, prepare just before use;

** - Light sensitive;

*** - Light sensitive, Mg2+ - inhibitor;

Preparation of stock solutions.

Ampicillin.

?filter sterilize; or prepare from the sterile water and the sterile powder;

?store at -20o C in small aliquots (avoid more than 10 freezing-thawing cycles);

?it is possible to use 50% glycerol instead of H2O. The advantage - solution is liquid at -20o C.

?some laboratories use 96% (or 50%) EtOH for ampicillin solubilization. There are two advantages in this method: (i) solution is liquid at -20o C, (ii) the solution is self sterilizing. But the disadvantage is very serious: ethanol is a weak catalyst of ?-lactam ring disintegration. So, solution is unstable.

Carbenicillin.

?filter sterilize; or prepare from the sterile water and the sterile powder;

?store at -20o C in small quantities (about 10 freezing-thawing cycles);

?200 μg/ml for pETpfu.

GE antibiotic mix (50x).

?filter sterilize; or prepare from the sterile KPO4 and the sterile powder;

?store at -200C, in small quantities (about 10 freezing-thawing cycles).

Tetracycline.

?solution in EtOH, store at -20o C;

?Mg++- antagonist, for the selection it is necessary to use Mg-free medium.

Chloramphenicol.

?store dry powder at 4o C, solution at -20o C (in EtOH);

?BL21(DE3)pLyzS - 34μg/ml -> 1μl for 1ml of medium.