Abstract: For high-resolution two-dimensional electrophoresis comprising the steps of carrying out, on a gel base, at first a first separation process in a first direction and then a second separation process in a direction vertical to the first direction by a technique different from that of the first separation, for example by molecular screening, it is proposed to use as a basis a dry gel consisting of a single piece and extending in the two dimensions and to hydrate the dry gel selectively in a strip-like area for carrying out the isoelectric separation in the first dimension, while the remaining gel area retains its dry gel configuration, to then perform the separation in the first dimension in the selectively hydrated area, and to hydrate thereafter the remaining electrophoresis area of the gel for carrying out the second separation process.