Herein is reported an expression vector comprising —an antibody light chain expression cassette, —an antibody heavy chain expression cassette, and —a selection marker expression cassette, wherein the expression cassettes are arranged unidirectional, and wherein the expression cassettes are arranged in the 5′ to 3′ sequence of antibody heavy chain expression cassette, antibody light chain expression cassette and selection marker expression cassette. Further are reported herein methods for the generation of antibody producing cells and the use of these cells for the recombinant production of antibodies.