stability of antibiotics. - (Sep/21/2007 )

can anyone tell me for how long ampicillin, kanamycin, spectinomycin, streptomycin and hygromycin are stable in LB-agar plates? what is the optimal temperature of their storage?

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there is decline of antibiotics efficacy over the time (weeks);

after some weeks it is difficult to estimate the effective concentration; better use the plates freshly poured, or store plates without antibiotics and add them freshly before use; in this case you should use a fixed volume (f.i 20 ml of agar) to calculate what you have to add

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