Two-dimensional diagonal SDS-PAGE was used to resolve membrane complexes and identify proteins with temperature-dependent mobility in Neisseria meningitidis and N. lactamica. The main membrane complexes were composed of porins and were formed by heteromers of PorA, PorB and RmpM in N. meningitidis, and by PorB and RmpM in N. lactamica. Also, other proteins, including Opa, with temperature-dependent mobility were clearly demonstrated. The method allows improved detection of the components of membrane complexes and proteins with temperature-dependent mobility which is difficult to resolve with other analytical approaches.