Loading controls, often called “housekeeping genes”, are being used for proper interpretation of western blots. They are used to normalize the levels of protein detected by confirming that protein loading is the same in all lanes of the gel. Of importance are constant expression levels that remain unaltered under various conditions, so that expression levels of the loading control do not vary between the different sample lanes.

It is also important that the protein chosen as a loading control has a different molecular weight than the protein of interest so that the bands are distinct and expression levels quantifiable. Popular loading control detection antibodies include anti-β-Actin monoclonal or polyclonal antibodies, anti-COX-4, anti-GAPDH, anti-Tubulin and anti-VDAC/Porin antibodies.