bacterial growth curve vs. O.D.

Frank Bartels fba at
Thu Aug 6 17:29:54 EST 1998

Franco Pagotto wrote:
> Hi all,
> Is anyone aware of an equation which takes into account an OD reading
> and gives or estimates the CFU's/ml of a bacterial growth?
> Tx.
> F.

Dear Franco,

The relation between cfu's and OD depends not only on the physiological
state of the culture. In addition the type of microorganism has to be
taken into account (e.g. the size of E. coli is different from
Bacillus). The best way is to count the cells to have the relation
between OD and cell number/ml. This should be constant. If every cell
forms a colony is a different question.


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