Total Protein Extraction by RIPA Protein extraction from tissues and cultured cells is the first step for many biochemical and analytical techniques such as protein purification, western blotting, as well as mass spectrometry. There is still no universal set of method or regent that is optimal for protein extraction due to the chemical/physical heterogeneity of proteins and their sample sources. Some factors should be taken into account when handling proteins such as sample types, subcellular locations of the protein, the compatibility of the protein as well as downstream applications. Here we provide a protocol for total protein extraction based on RIPA which is widely used. Notes: All reagents and instruments must be pre-cold to reduce protein degradation. Extract total protein quickly and efficiently. Add 10 µL sodium orthovanadate solution and 10 µL protease inhibitor cocktail solution per 1 mL of RIPA lysis buffer before use to prevent proteolysis and maintain phosphorylation of proteins. Protein production should be store at -80°C. https://www.creative-diagnostics.com/total-protein-extraction-by-ripa.htm