Mammalian Cell Protein Extraction Buffer has been designed for fast and easy extraction of cytoplasmic and nuclear proteins from cultured mammalian cells, which require no or little mechanical disruption. This utilizes a proprietary mild and non-denaturing detergent and is effective in extracting and solubilizing total proteins from most cellular compartments. In addition, it also offers several fold increase in the yield of soluble proteins and the extracted proteins are stable, since there is no repeated freezing and thawing steps.