Hi to everybody! I am struggling with Silver Staining, I am preparing a BSA curve but I see often bands around 20 kDa that are not expected and I have a strange gel background as you can see from the picture. The part on the right is not broken, is only something related with the staining (before that was not visible at all).

I want to point out that I treated the gel carefully, avoiding to touch it (except in the corner for moving it to the solution container).

Solutions fresh prepared, except the washing solution (EtOh 30%) that was prepared one week ago. 

I need hints as I am learning this technique alone! 

Our protocol uses sodium thiosulfate 0.02% to sensitize the membrane. 

0,2% AgNO3 to stain (with a small percentage of Formalin)

And sodium carbonate to develop (with a small percentage of Formalin).

The stop reaction is mediated by a glycin solution.

Thank you very much!