SDS-PAGE problem with staining yellow background - (Jun/09/2012 )
I started to have serious problems with SDS-PAGE staining. I'm using a "Safe Stain" protocol for staining. After run, when I put a gel into stain and microwave it, I see very strange yellowish color of a gel (it is sort of weird blue-yellowish color, in fact). The strange thing, when I stopped one of gels earlier, I have noticed an clear difference between two parts: the half with yellowish color was the same as buffer front was moving down; where the buffer didn't run, there were no intense yellowish background! I never had this problem before. The only difference if that I have made a new running buffer with new chemicals. I believe that there are problems with chemicals (contaminated/degraded).
I have seen glycine go yellow in solution - it is probably contamination of some sort, but I don't know what with.
check the pH of your buffers
The spoiled chemicals....