Not fully polymerized stuff in the wells of SDS-PAGE - (May/03/2008 )

Hi, I make my own SDS-PAGE gels for running protein samples simply by mixing each ingredient. It used to work well without any problem. But recently I always get some not fully polymerized stuff in the wells after I remove the comb. These stuff, if not removed, can block my samples from settling down to the well or shape my samples into weird shapes. I tried to use running water to get rid of them but it didn't work. I prepared new APS and again it did not work. The gels seem to be polymerized just fine except for this little (but really annoying) problem. I have to use needles to get rid of them, but sometimes I poked my gel which, of course, did not turn out well.
So I was wondering if anyone knows why this occurs and how to solve this?
Thanks

before loading samples in the wells, wash it with a syringe and this will help to clear the unwanted stuff in the wells.

three potential and non-exclusive causes of this phenomenon are degraded temed, warped plates and poorly engineered spacers.

degraded (or contaminated) temed will cause the gel to polymerize more slowly. you may think it is finished polymerizing but it may not be and low percentage gel polymerizes even more slowly.

warped plates won't allow even contact with the comb across the width of the plate. you will find the "skins" more in the middle than at the edges of the plate (we have had this problem, to overcome it we clamp the top of the gel after the comb has been inserted).

spacers may be slightly thicker than the comb (it doesn't take a lot to cause a problem). additional clamping may help.

there may be other causes but i can't think of them at this time.

when we get skins, we scrape them out with a thin spatula. some of the other labs here use a fine needle attached to vacuum to suck out the skins (with or without a little buffer in the well).

Thanks for the information...