How to prepare SOB agar plate - If it possible to add all chemicals before autoclaving (Dec/07/2010 )

Hi..

I will appreciate it very much if someone could help me on a protocol to make SOB agar plate.
The point is that I understand from a text that it is recommend to prepare SOB media by adding Tryptone , Yeast Extract, NaCl, KCl and autoclaving. then add solution of MgCl2 + MgSO4 before use.

I wonder if I could add MgCl2 + MgSO4 and agar before autoclaving in order to prepare SOB agar plate.
Or if who know the correct protocol, please help.

Thank very much in advance for your suggestion
Sincerely,
Urai

Hola, you could autoclave together Tryptone, Yeast extract ,sodium cloride, potasium cloride and agar. Separatelly autoclave magnesium salts, (in other cases to other media the same for calcium and sugars) and before platting add Mg,(sugars, Ca++, vitamins or antibiotics,in other media).if you made all together ,Mg or Ca can precipitate, sugars can caramelyze, vitamins and antibiotics hidrolyze. Buena suerte