Stain-Free total-protein normalization enhances the reproducibility of Western blot data

Abstract

We compared the accuracy of three common methods of total protein normalization. The Stain-Free method was accurate across different types/brands of western blotting membrane and for various protein loads, unlike Ponceau S and Amido Black. Normalizing to the housekeeping proteins Actin and β-Tubulin could match the accuracy of the Stain-Free method. However, compared to Actin or β-Tubulin, normalizing to the Stain-Free signal reduced variability that led to enhanced reproducibility and a reduction in the number of samples needed to obtain statistically significant results by >50%. Stain-Free normalization can enhance the reproducibility and hence the confidence in Western Blot data.

Keywords: Amido black; Ponceau S; Rigour and reproducibility; Stain-free; Total protein normalization; Western blot.