Membrane proteins play pivotal roles in biological processes, such as connecting cells to each other and to the cell matrix, organizing the shape of the organelles and the cells, and transporting ions, metabolites, proteins, RNA and other biomolecules. Improved methods that reduce barriers to membrane protein extraction, stabilization, crystallization and structure determination accelerate membrane structural and functional investigation.

Extraction of membrane proteins from phospholipid bilayer is the first step of purification and structural characterization. The common problems are: (1) the interested membrane protein is not efficiently extracted from the membranes, or (2) the protein is extracted in an inactive form. The key of membrane protein extraction is to destroy the bilayer structure to remove the protein without irreversibly disrupting the protein structure. The main agents used to extract membrane proteins are amphiphilic molecules, such as detergents, which can replace and mimic the stability of natural phospholipids. An increasing number of products are being specially developed for extraction of membrane proteins.