Please post...

[JM Warawa, Department of Pathology & Microbiology]

Everyone,

I have been having a problem with extra bands on my SDS 
PAGE (about 55 and 65kD).  I have only had the problem 
since moving to England from Canada.  I have tried using 
both beta-mercaptoethanol, and DTT in the sample buffer, 
but get the problem with both reducing agents (even more so 
with DTT!). I see the problem showing up when I probe a 
western with rat polyclonals, but I have also seen these 
bands when doing a coomassie with DTT in the sample buffer. 
It looks like something in the acrylamide matrix is being 
reduced and 'running' on my gel.

Any help?  Thanks,
Jonathan Warawa