The invention provides amphiphilic compounds and methods for manipulating membrane proteins. Compounds of the invention, for example, the compounds of Formulas I-XIX, can be prepared from readily available starting materials. The amphiphilic compounds can manipulate membrane protein at relatively low concentrations compared to many known detergents. The compounds can be used to aid the isolation of membrane proteins, for example, to aid their solubilization and/or purification. The compounds can also be used to aid the functional and structural determination of membrane proteins, including their stabilization and crystallization.