SDS and acetate in DNA isolation

Austin P. So (Hae Jin) nobody at nowhere.com
Fri Oct 14 21:30:37 EST 2005


I don't think it is a matter of people don't know, just that people 
choose not to know...which is unfortunate really...

Basically, the general principles of the miniprep are the same, 
regardless of the method chosen (alkaline lysis or boiling).

1. punch holes in the cell wall. The idea is that timed degradation 
(NaOH or lysozyme) will create a "cage" in the peptidoglycan wall. 
Eventually, the holes are large enough to let out plasmid, but small 
emough that genomic DNA is retained within the "cage". Too long of an 
incubation leads to release of genomic DNA, too little leaves a lower 
yield of plasmid.

2. Solubilization of the cell membrane through treatment with detergents 
such as SDS to release cell contents.

This is not to say that SDS doesn't have a role in #1, but again, this 
is generally how it works.

Austin

Rafael Maldonado wrote:

> That counts for the citoplasmic membrane and, maybe, the outer membrane. 
> But, what about the inner membrane, which is made of peptidoglycan?
> 
> I still think nobody knows how realy it works, but because it does, who 
> cares??
> 
> -R
> 
> 
> 


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