Thiamine in M9 minimal medium

Patrick Druggan Patrick.Druggan at
Thu Sep 21 17:22:49 EST 2000

I have a couple of questions.

1. What colour is the medium after autoclaving?
2. What is the pH?

"Emir Khatipov" <ekhatipo at> wrote in message
news:Jmzx5.80$v3.1796 at uchinews...
> Hi,
> I have problems with growing TOP10 transformants in M9 minimal medium.
> Could someone experienced in using M9 minimal medium advise me what is the
> most appropriate way of preparing and handling/storing thiamine solution.
> What should be the concentration of the stock solution so that thiamine
> dissolve readily in water, and whether it should be prepared fresh or can
> stored, how long? I was advised to add up to 10ug/ml thiamine to the
> and I make 1000 x water solution by mixing thiamine crystals with water
> adding alkali.
> The TOP10 cells I am using cells that are L-lysine auxotrophs, so any
> additional comments on lysine solution would be appreciated, too (making,
> storing).
> I make the M9 medium according to conventional protocols. Since there is
> nothing special about M9 salts and glucose, I don't think I am screwing
> something up there. I guess my cells do not grow because I do something
> wrong when making thiamine or lysine.
> I know thiamine is light-sensitive and I store it in the dark. Anyway, I
> could not get my cells grow even with freshly made thiamine solution.
> I also know that I could add up to ~4% LB to facilitate growth, but I do
> want to do that.
> Thanks.
> Emir

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