A Western blot provides a readout of differences in protein expression levels e.g. changes in protein levels over a certain time period, differences in knock-out versus wild type cell lines and altered expression in patient samples. However, in order to draw any conclusions from a Western blot one has to be sure that the observed differences are only due to altered protein expression levels rather than gel loading or protein transfer errors. For this purpose Western blot loading controls are used.
|Sample type||Loading contol||Molecular weight (kDa)*|
|Whole cell/cytoplasmic||Alpha actin||43|
|Mitochondrial||Cytochrome c oxidase||16|
|TATA binding protein TBP||38|
|*The exact molecular weight might vary from species to species|
What is the most commonly used loading control in your lab?