Gels keep cracking

[Richard V. Giles]

"S. McKay" wrote:
> 
> Hi,
> 
>         I've been having some problems drying mini-gels.  I'm using 14%
> SDS-PAG to separate my protein (which is 35S-labelled).  Following this I
> have been fixing the gels in 7% Acetic Acid for 20', rinsing in dH2O and
> then an amplification step using 0.5M Salicylic Acid for 20'.  The gels are
> then dried onto Whatmans 3mm Chromatography Paper under vaccum and heat on
> a BioRad Gel Slab Dryer for 1.5hrs.  Less time than this and the centre of
> the gels do not dry.  Unfortunately, I've been experiencing severe cracking
> problems with the gels which is obviously unacceptable.
> 
>         I am aware that the salicylic acid will remove much of the moisture
> from the gel but 1.5hrs seems a long time.
> 
>         I've also tried  using the 0.5M Salicylic Acid combined with 2%
> glycerol but this makes no difference and if anything the cracking is
> worse.
> 
>         This has become a very frustrating problem and any suggestions you
> could make would be very much appreciated.
> 
> S.McKay

I'd up the glycerol content to 10%.

In the past when we've dried SDS PA gels the final step was 5% acetic
acid, 10% glycerol. No cracks when dried as you have described. Don't
know how the 0.5M salicylic acid would interact with this though...

-- 
Richard V. Giles Ph.D.
School of Biological Sciences
University of Liverpool
Tel +44/151 794 4389
Fax +44/151 794 4349
http://www.liv.ac.uk/~giles/