"Paul Wary" <paul_wary at yahoo.com> wrote in message
news:c4879cbb.0409081354.4575f088 at posting.google.com...
>> I am going to express a protein in E. coli host cells (to be precise
> BL21 (DE3) cells) and the instructions say that the induction of
> protein synthesis through IPTG is to be started at an OD of 0.6, which
> is easy enough.
> The cells are then grown to saturation before harvesting (no OD given
> for saturation).
> Can anyone tell me what the approximate OD value of a saturated E.
> coli culture is?
OD is only a very rough guide to cell number or mass. When it stops
increasing you're probably there.