Membrane protein studies have advanced significantly over thepast few years. This is partly due to advances in tools and reagentsused to manipulate this class of proteins. Detergents play anessential role in the extraction, purification, and manipulation ofmembrane proteins; their amphiphilic nature allows them tointeract with hydrophobic membrane proteins to keep themwater-soluble outside of their native bilayer environment.Unfortunately, solubility does not always translate to nativestructure and stability; a detergent that is useful for extractionmay not be compatible with purification and/or biochemicalstudies. Furthermore, a detergent that works for one membraneprotein may not be suitable for a different membrane protein.While there is not a set of “golden rules” for the uses ofdetergents for membrane protein applications, understanding the physical-chemical properties associated with different classesof detergents may be useful for deciding which detergent maywork best for a particular application. For example, the ioniccharge or degree of hydrophobicity of a detergent molecule willdictate how it will function in solution and thus how it willinteract with membrane proteins. The purpose of this handbook is to introduce the researcher to the physical and chemicalproperties of detergents and describe how these properties relate to detergent function.