Guanidine and SDS-page gel

[Bean Long]

Sophie wrote:
> I read on this forum that it is possible to run guanidine samples if 
> they are diluted. Which final concentration of guanidine do you 
> recommend to avoid SDS precipitation?
> Thanks,
> Sophie

I'd recommend urea instead if possible. 8M urea in samples is not a 
problem for SDS-PAGE. Unfortunately I learned this a long time ago after 
a dreadful experience with guanidine and now can't recall the lowest 
reasonable concentration for loading. Best of luck.