One step transformation

kang at kang at
Tue Feb 28 06:39:49 EST 1995

In article <3itgh6$g3h at>, Glen Shearer <gshearer at> writes:
>Anyone tried the Chung et. al, PNAS.  86:2172-2175 (1989) one step
>transformation & storage of E. coli?  As I recall, the authors use
>a solution of PEG + MgCl (called TSS) to resuspend log phase cells
>and get a reported 10^8 transformants per ug.
>I've tried this method with several strains and get at best 10^5
>transformants/ug with various pUC vectors.
>I'm curious if anyone has had this work in the 10^8 per ug range and
>if so, what is the secret technique.
>[gshearer at]

I used modified methods of this and usually could get 10^8 per ug.
I think the method was reported 1992 by Nishimura et al.
If you can not find the protocol send me e-mail. I have a copy in my lab.
One thing I want to mention is if you want to get more than 10^7 per ug DNA you
should use DNA less than 100 pg. If DNA is to much there will be a significant
decrease of transformation because of saturation effect.
Good Luck

Chulho Kang

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