Abstract: The invention is a method for selectively isolating cells which secrete higher levels of monoclonal antibody than did the parental culture from which they were derived. The method is based on the membrane characteristics of the cell and requires the use of a cell sorter. At present, the invention's best mode utilizes fluorescent probes in conjunction with a fluorescence activated cell sorter. The method is based on the correlation of a high level of cell surface immunoglobulin with high monoclonal antibody secretion rates. The invention provides a predictable and rapid process for selecting high monoclonal antibody producing cells.