I performed silver staining using a standard protocol. But the problem is As soon as I add silver nitrate to gel, the solution turns white and the gel becomes white. What could be the reason for this? How can I overcome it?
As Susanna Karkkainen and Vello Tougu suggested, it is likely that your gel is in a solution that is contaminated with salts, especially chloride. Silver chloride is insoluble in water.