Electrochromatography (ECHR) exploits a very high electro-osmotic counterflow developed in porous membranes at discontinuous electrophoresis. This counterflow exceeds considerably the anodic migration of any negatively charged protein and is used as a 'conveyer belt' for sequential transfer of immunoreagents to the specific adsorbents (antigens or antibodies) fixed on the nitrocellulose membrane. This approach was applied for simultaneous detection of two antigens (alpha-fetoprotein and carcino-embryonic antigen) in one sample, for determination of subfractions of alpha-fetoprotein, different in their epitope specificity, and for detection of L chains with certain idiotype on the background of heterogeneous L fraction. ECHR was used also for the partition of different antibodies to DNA adducts, demonstrating the possibility of applying this method to the study of DNA-binding proteins.