Blue Background on Gel or Blot After Electrophoresis (Western Blot (Blue Background))

Question

Accepted Answer

After completing electrophoresis, the gel or blot membrane displays a diffuse blue background coloration instead of a clear background. The blue tint is distributed across the gel surface or transferred to the membrane. Common causes: 1) Cathode buffer dye containing Coomassie blue G was not removed or replaced during electrophoresis 2) Cathode dye (Coomassie G-containing) remained present throughout the entire first dimension separation 3) Premature termination of electrophoresis before dye could migrate out of the gel 4) Insufficient electrophoresis time after dye buffer replacement to clear residual Coomassie blue G Solutions: 1) Replace cathode dye buffer with cathode buffer without dye when first dimension separation is almost complete 2) Continue further electrophoresis to allow most of the Coomassie blue G dye to migrate out of the gel 3) Monitor the dye front during electrophoresis and perform buffer exchange before the run is complete 4) Ensure adequate electrophoresis run time after dye buffer removal to clear background staining