SDS Page sample buffer - (Sep/22/2008 )

I am facing a problem while running my SDS PAGE gel. When i run my samples along with sample buffer after running for a while in the gel the sample buffer color is changing to yellow color. Why is it so. Can anybody explain me.

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Bromophenol blue changes color to yellow below pH 3.0.

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Why does the pH changing after running for more than an hour.

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because buffer components also migrate in the gel.

does the bpb return to blue before the end of the run? if so then there is, most likely, no problem.

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No its not returning to blue color and once it changes to yellow color even the movement of the protein is dead slow

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Then you should check the pH of your running buffer as well as your gel solutions pH (running gel, stacking gel). It should net get that yellow during the run. Something seems to be wrong with your pH and/or ionic condition in the running gel.

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