Question on Liquid vs. Solid Media with Invitrogen's TOPO-10 bacteria!

Gregg Silk greggsilk at
Wed Jul 8 20:04:23 EST 1998

>in LB liquid medium, in comparison to LB--agar medium (both with 50ug/ml
>ampicillin).  I also attempted to grow up the colonies in SOC medium
>(50ug/ml ampicillin), 

50 ug/ml is only sufficient if you have a low-copy number plasmid(pBR322). The
selection isn't strong enough and the plasmid is lost.  If this is a pUC
derivative, use 150 or even 200 ug/ml AMP. I'd guess the plasmid in teaching
lab is some sort of pUC.

SOC is peferred for growing transformants because it has a better concentration
of various salts. Also, the higher amounts of yeast extract in LB is bad for


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