Checking transfer efficiency and equal loading via qualitative optical way in western blotting

Abstract

The ability to determine that successful transfer and equal loading occur prior to using primary antibodies is important. And total protein staining is commonly used to check transfer efficiency and normalization, which play a crucial role in western blotting. Ponceau S and coomassie blue are commonly used, but there are disadvantages reported in recent years. Therefore, we are interested in finding another method, which is cheap, easy and fast. As we know, protein binding region of PVDF membrane is still hydrophilic when carbinol volatilizes, however, the non-protein binding region of PVDF membrane became hydrophobic again. And this different wettability between non-protein binding region and protein binding region of Polyvinylidene difluoride membrane may be used to check transfer efficiency and equal loading in western blotting. Based on the principle above, we describe an optical approach where an experimenter can observe that the proteins have been transferred to the membrane without any staining within minutes.

Tubulin or Not Tubulin: Heading Toward Total Protein Staining as Loading Control in Western Blots

“…Further, a stain‐free visual inspection of the transfer efficiency has been suggested, but as the method is non‐quantitative, it cannot be used to compensate for loading differences …”