syber green

[Rich Kernan]

In article <4dlmpe$2os at gatekeeper.kcc.com>, "K.G. Korth" <kkorth at kcc.com> wrote:


> 
> I have tried SYBR I Green in loading buffer (standard 6X TBE loading 
> buffer with 1:10,000 SYBR I Green) as recommended by a newgroup poster 
> about 6 months ago and found the migration to be significantly affected 
> by the SGI, such that the bands that were supposed to line up, no longer 
> did (including my ladder DNA).  Same thing happened when adding the SGI 
> to the agarose itself rather than the loading buffer. Though it did work 
> as a post run stain, it is just too expensive to use that way and really 
> gave us no better results than the EtBr (as a post run stain).
> 
> I love the sensitivity of SGI and the very low background, but I could 
> not tollerate the way it affected migration.  We no longer use it for 
> anything.
> 


I have tried several methods of SGI staining and have reached the same
results as above.  I have tried several differnet running buffers as
recommended by 
molecular probes.  Each time the migration was altered so severely as to
make size determination impossible.  So I guess the prohibitively
expensive post   staining is the only useful method.  If anyone has found
a way to prestain with SGI then PLEASE post it.