bacterial growth - (Feb/26/2009 )

hi all

i have a very basic problem my e.coli cells(DH5alpha cells) had grown in lb with amp(100mg/l) but when i raised culture from the same fresh plate with half amp concentration there was no growth. this problem has been persistent . im nt able to find the answer.can anyone give me any suggestions plz?

thanks in advance

Hey

Was the antibiotic stock u used for both experiments (plates and culture) the same?

How old were the plates that you used?


TC