Pipetting, contamination....

peter via methods%40net.bio.net (by peter.ianakiev from gmail.com)
Thu Feb 22 22:45:57 EST 2007


On Feb 22, 10:26 pm, d... from no.email.thankstospam.net (DK) wrote:
> In article <1172199429.419560.225... from p10g2000cwp.googlegroups.com>, "peter" <peter.ianak... from gmail.com> wrote:
>
> >On Feb 22, 9:09 pm, d... from no.email.thankstospam.net (DK) wrote:
> >I guess we will find out.... sometimes bacteria will fail to grow if
> >you seed directly to >100 ml (even if you pick from a colony), that's
> >why people make small culture overnight.
>
> Nope, people make small cultures overnight to make sure they've got
> saturated cultures no matter how much of the cells they inoculated,
> certainly not because bacterial cells die when diluted.
>
> Having uniform saturated cultures can offer various advantages
> such as a) inoculating larger cultures with ~ the same amounts
> so that the desired density is reached ~ at the same time, b) having
> maximal amount of plasmid per cell.
>
> Inoculating into larger volumes will only increase lag phase, but with the
> difference between 2 ml and 100 ml of only 50X ~ 6 doublings, I can't
> see how it would make an all ot none difference. An eye easily picks
> turbidity at as low as OD600=0.05.
>
> DK

DK , I did not say that bacteria die, I said it can fail to grow -
especially if you have ampicillin, which is bacteriostatic.
my2c



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