Detergents are frequently used in molecular biology studies, such as cell lysis, protein purification, DNA/RNA isolation, electrophoresis, immunoassays, cleaning, and more.
Detergents are amphipathic compounds, consisting of a hydrophilic domain and a separate hydrophobic domain. Detergents spontaneously form spherical micellar structures in aqueous solutions to provide an amphoteric environment that mimics lipid bilayers. The high aqueous solubility of detergent molecules has given them a crucial role in the extraction, purification, and stabilization of membrane proteins and in experimental studies of their structure and function.
Detergents are classified into three major categories according to their structure:
Ionic detergents contain a head group with a net charge of either cationic or anionic, which are extremely effective in the solubilization of proteins but also denaturant them.
Nonionic detergents contain an uncharged hydrophilic head group, which are generally considered to be mild. As nonionic detergents are preferred to break lipid–lipid interactions and lipid–protein interactions rather than protein–protein interactions, many membrane proteins are solubilized in nonionic detergents without denaturation.
Zwitterionic detergents combine the properties of ionic and nonionic detergents, which have little effect on proteins, but they are often more efficient at breaking protein-protein bonds.