Sodium thiosulfate-free silver staining for PAGE v1

This protocol describes a silver staining method for visualizing proteins separated by SDS-PAGE without using sodium thiosulfate as a sensitizer. The procedure involves fixation of the gel to immobilize proteins and reduce background, followed by impregnation with a silver nitrate solution that binds to the protein bands. After rinsing off excess silver, the gel is developed using a sodium carbonate and formaldehyde solution, which reduces silver ions to metallic silver at protein locations, creating visible bands. The reaction is stopped with a Tris-acetic acid solution to stabilize the image and prevent overdevelopment. Final washes remove residual chemicals, resulting in sensitive protein detection with minimal background. This thiosulfate-free protocol is recommended when downstream applications like mass spectrometry require avoidance of certain chemical interferences.