Lauryldimethylamine oxide (LDAO), also known as dodecyldimethylamine oxide (DDAO), is an amine oxide based nonionic surfactant, with a C12 (dodecyl) alkyl tail. It is one of the most frequently-used surfactants of this type. Like other amine oxide based surfactants it is antimicrobial, being effective against common bacteria such as S. aureus and E. coli, however it is also non-denaturing and may be used to solubilize proteins. Lauryldimethylamine oxide (LDAO), also known as dodecyldimethylamine oxide (DDAO), is an amine oxide based nonionic surfactant, with a C12 (dodecyl) alkyl tail. It is one of the most frequently-used surfactants of this type. Like other amine oxide based surfactants it is antimicrobial, being effective against common bacteria such as S. aureus and E. coli, however it is also non-denaturing and may be used to solubilize proteins. At high concentrations, LDAO forms liquid crystalline phases. Despite having only one polar atom that is able to interact with water – the oxygen atom (the quaternary nitrogen atom is hidden from intermolecular interactions), DDAO is a strongly hydrophilic surfactant: it forms normal micelles and normal liquid crystalline phases. High hydrophilicity of this surfactant can be explained by the fact that it forms very strong hydrogen bonds with water: the energy of DDAO – water hydrogen bond is about 50 kJ/mol.