On Thu, 29 Sep 2005 16:20:14 -0400 (EDT), Monalisa Sunkara
<msunkara at uncc.edu> wrote:
>hi,
>I am trying to grow E.coli in M56 salt medium supplemented with glucose
>by picking a colony from 2-3 days old E.coli SM agar plate and
>incubating in 10 ml of M56 o/n at 37 degress and 187 rpm as mentioned
>in literature.But i am not getting OD (550nm)=2 after o/n incubation as
>is mentioned in the literature.Rather i am getting OD of only 0.2.Any
>suggestions?
Are they growing well? If you let them grow some more, do they get to
the higher density? If not, you may have a sick strain (or inadequate
growth medium). Note that the difference between OD 0.2 and 2 is only
3 generations. That is not very long.
If it is just a matter of time, make some adjustments. You might try
older or younger colonies. The result is not entirely predictable;
just do what works. For example, if the plates are dense, colonies age
faster (and are smaller).
The suggested protocol is just rough. You need to check it and adjust
it.
(Are you sure you are aerating adequately? Can't tell from given info.
Maybe try higher aeration??)
bob
