The invention relates to a method for the detection and multiplex quantification of analytes in a sample, using functionalised microspheres, whereby said microspheres are magnetised after the sample has been brought into contact therewith. The inventive method is particularly suitable for the detection and multiplex quantification of several analytes by means of flow cytometry. The invention also relates to a kit which is used for the detection and/or quantification of several analytes in order to carry out the inventive method, comprising a suspension of functionalised non-magnetic microspheres, a ferrofluid solution and a solution with at least one conjugate.