M9 medium/minimal

From OpenWetWare
Revision as of 11:17, 30 March 2006 by MDolinar (talk | contribs) (added 2 notes)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

We used to prepare the plain M9 medium as follows:

900 ml sterile water
100 ml M9 salts stock solution
1 ml autoclaved 1 M MgSO4
0.1 ml autoclaved 1 M CaCl2

M9 stock solution (10x) is:

60 g Na2HPO4 x 7 H2O
30 g KH2PO4
5 g NaCl
10 g NH4Cl
add water to 1000 ml and autoclave


Note 1: salts that are added last often tend to precipitate. I didn't bother about it too much as obviously it didn't influence bacterial growth. There might be a way to avoid precipitation (eventually adding magnesium and calcium first) but I didn't investigate this in detail.

Note 2: The M9 stock solution here is essentially as in the M9 salts recipe just that the concentration is about half of that. Nevertheless, bacteria are normally OK with this.