BL21 and LB media - (Aug/22/2008 )

Hi,
I want to transfect my BL21 strain and I have hips of prepaied LB media. I want to know if it is OK to use the 2X LB as a transfection media instead of SB or any other recomended media.


Thanks

umm... may I ask what exactly is 2x LB?

If 2x LB is twice the amount of premade LB powder in the same volume... I am not sure. The NaCl concentration would be rather high. I would guess that this would not be be a good environment, given the fragile state of the cell wall and cell membrane of the E.coli after transformation.

If the salt is added later (and thus normal salt concentration is used) the medium should be okay. E.coli would probably like more Magnesium, but it probably should not make a visible difference.

so 2x Lb will have 10g/l of NaCl.... I don't think that would be a good thing. However, 10g/L NaCl has appeared in old LB formulations (the original by Luria Bertani). So it might work, although given the fragility of the cell membrane, and the high osmotic pressure caused by the 10g/L salt, I don't know if the media will work better than normal LB.

I guess the only thing I can say to use is give it a try. 2xLB, LB, and if you can find SOC medium. And see which medium is better.