Hi Urooj

Is it for staining protein in a SDS-PAGE gel? If yes, do you cast your own gels or do you use pre-cast commercial gels?

For silver staining you need to have very well cleaned glass plates and other material!

I am doing native PAGE gel for enzyme proteins

Be sure to have all glass equipment absolutely clean. Soap, ddH2O and ethanol or acetone. 

Maybe the concentration of substrate for the enzyme reaction is too high. 

Meet me

Here are my recommendations:

1. Use fresh SDS running buffer

2. Use only mQ water or dH20....avoid tap water for cleaning 

3. minimize hand contact (or glove contact) with the gel...in other words, do not touch gels!

4. Check your sample buffer for possible protein contamination....if possible, use fresh one.