gel does not polymerize - (Oct/26/2010 )

you can add aps and temed in amounts that would allow your gel to polymerize in 5 minutes (or less) but the heat generated would cause convection and the structure would be questionable. also, adding more temed causes shorter strands and a brittle gel (thanks for the info, tfitzwater). we use enough aps and temed so that our gels are nearly fully polymerized within an hour (we let them sit longer to ensure complete polymerization), but we usually pour gradients and need the working time.

what color is your temed? if it is (very) yellow then it may have decomposed too much to continue using the same amount. ideally, you should obtain fresh temed.

aps is somewhat hygroscopic. we store it at room temperature with a silica gel packet in the bottle. for us, it lasts for years.

we overlay with isobutanol because it isn't miscible.

Thanks mdfenko thats very informative.Our Temed is a little yellow so we are ordering new Aps, acrylamide and Temed. How do you normally mix your solution by the way? Do you give it a gentle shake?
Thanks.

depending on the vessel we mix by swirling or inversion or both (not too vigorously).