Mass spectrometry has become a popular method for analyzing and characterizing proteins. Traditional total protein extraction methods, such as RIPA-based reagents, can alter endogenous baselines due to nonsystematic protein loss. Some chemicals in RIPA may not be compatible with mass spectrometry and other downstream applications. This kit extracts total proteins quickly using a specially formulated lysis buffer and proprietary spin column. The extracted proteins are compatible with trypsin digestion followed by MS analysis, iTRAQ, biotin labeling, etc. Due to the use of filter cartridges, the extraction volume can be as low as 20 µl – a helpful feature when starting material is a limiting factor. The typical yield is 2-8 mg/ml.