Preparing protein extracts for quantitative two-dimensional gel comparison.

This unit describes basic protocols for efficient and reproducible protein solubilization from a variety of biological samples, including cultured animal cells and tissues, plant cells and tissues, bacteria, nuclei, other subcellular organelles, plasma, serum, and other biological fluids. The optimized extraction process is strongly sample-dependent and cannot be described for every type of sample. Instead, typical protocols are provided as general guidelines and illustrate good starting points for sample-preparation optimization. These solubilization procedures take into account the constraints brought by two-dimensional electrophoresis and are thus well suited for proteomic approaches.