A Protocol for Protein Extraction from Lipid-Rich Plant Tissues Suitable for Electrophoresis

Plant tissues contain high levels of nonprotein contaminants such as lipids, phenolic compounds, and polysaccharides among others, which interfere with protein extraction and electrophoretic separation. Preparation of good-quality protein extracts is a critical issue for successful electrophoretic analysis. Here, we describe a three-step method for protein extraction from lipid-rich plant tissues, which is suitable for both 1-D and 2-D electrophoresis and is compatible with downstream applications. The protocol includes prefractionation, filtration, and TCA/acetone precipitation steps prior to protein resolubilization.