Abstract: A method and device is disclosed for rapidly identifying a large number of proteins by placing a protein mixture in a sample chamber of an electrophoresis gel, and performing electrophoresis to separate the mixture by molecular weight, in a direction of separation, into a two-dimensional separation pattern in the gel. The separation pattern is transferred to a membrane, such as a sheet of nitrocellulose, and a plate with a set of separate, side-by-side slots is then applied to the membrane. A different antibody mixture is introduced into each of the slots by perfusing each antibody mixture under pressure through the slots. The antibody mixture that is perfused through each slot recognizes several different proteins of sufficiently different molecular weights that different protein bands can be resolved by the antibody mixture in each slot.