Solid-supported lipid/DNA complexes were prepared by using highly aligned 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) multibilayers as a template. The complex formation was promoted in situ and followed in time. The resulting DOTAP/DNA complex shows a good degree of orientation along the normal to the support as revealed by combined time-resolved energy dispersive X-ray diffraction (EDXD) and surface synchrotron small angle X-ray scattering (SAXS) measurements. (c) 2005 Elsevier B.V. All rights reserved.