The present invention relates to a cartridge (1) for the detection of an analyte (2) in a binding assay with magnetic labels (3), the cartridge comprising at least one capture binding agent (4) against a binding site on the analyte and comprising at least two magnetically labelled tracer binding agents (51 and 52) against further different binding sites on the analyte, characterized in that the cartridge comprises at least two regions (61 and 62) wherein a first region (61) comprises the at least one capture binding agent (4) and a first magnetically labelled tracer binding agent (51) and wherein a second region (62) comprises at least one capture binding agent (4) and a second magnetically labelled tracer binding agent (52). Herein the first region (61) does not comprise a magnetically labelled tracer binding agent other than the first magnetically labelled tracer bind agent (51) and wherein the second region (62) does not comprise a magnetically labelled tracer binding agent other than the second magnetically labelled tracer binding agent (52).