Weird SDS-PAGE... HELP!!

Alan Kaiser alkaiser at
Tue May 9 19:02:46 EST 1995

In <95128.132452JPS144 at> Joe Stains <JPS144 at> writes:

>Someone in my lab is running SDS-PAGE on a cell lysate.  However, when
>they run the gel, the sample lanes spread out (longitudinally), pushing
>the adjacent lanes out as well.  No one seems to have seen anything like
>this before.  We've tried several things to reduce salt, getting rid of
>any lysis buffer, decreasing sample load volume, but nothing seems to
>work.  We've even decreased the gel speed to hopefully correct the

I have also experienced this same problem. I run 20% gels and my
samples contain peptides. Overloading the well with protein or high
salt content are the explainations I have been given but in many cases
this just can't be the case and it still happens. When I run a pure
sample of this peptide at concentrations that are only visible by
silver staining, too much protein just can't be the reason! 

One thing I have found that helps a lot is to make sure that all lanes
have something loaded in them and that the volume in each well is
roughly the same. Doing this minimizes the spreading but still does
not prevent it. 

Another poster indicated that the problem may be due to the physical
setup of the apparatus. I have consistantly had this problem for about
two years now and it doesn't matter if the gel is stored or not. I
have tried storing the entire gel overnight, storing the running gel
overnight and pouring the stacking gel just before loading, pouring
the whole gel the day of running etc. etc. and I still get the same
results. Sometimes it's worse than others but it is not consistant
with anything that I am physically doing so I have assumed it is the

Any other suggestions!

Alan Kaiser			alkaiser at
Graduate Program in Microbiology and Molecular Genetics
Rutgers University               New Brunswick,NJ

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